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  • 201.
    Pavlou, AK
    et al.
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; Gloucestershire Royal Hospital, PHLS and Gastroenterol Unit, Gloucester GL1 3NN, England; .
    Magan, N
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; Gloucestershire Royal Hospital, PHLS and Gastroenterol Unit, Gloucester GL1 3NN, England; .
    Sharp, D
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; Gloucestershire Royal Hospital, PHLS and Gastroenterol Unit, Gloucester GL1 3NN, England; .
    Brown, J
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; Gloucestershire Royal Hospital, PHLS and Gastroenterol Unit, Gloucester GL1 3NN, England; .
    Barr, H
    Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; Gloucestershire Royal Hospital, PHLS and Gastroenterol Unit, Gloucester GL1 3NN, England; .
    Turner, APF
    Cranfield University, UK.
    An intelligent rapid odour recognition model in discrimination of Helicobacter pylori and other gastroesophageal isolates in vitro2000Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 15, nr 08-jul, s. 333-342Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Two series of experiments are reported which result in the discrimination between Helicobacter pylori and other bacterial gastroesophageal isolates using a newly developed odour generating system, an electronic nose and a hybrid intelligent odour recognition system. In the first series of experiments, after 5 h of growth (37 degreesC), 53 volatile sniffs were collected over the headspace of complex broth cultures of the following clinical isolates: Staphylococcus aureus, Klebsiella sp., H. pylori, Enterococcus faecalis (10(7) ml(-1)), Mixed infection (Proteus mirabilis, Escherichia coli, and E. faecalis 3 x 10(6) mi each) and sterile cultures. Fifty-six normalised variables were extracted from 14 conductive polymer sensor responses and analysed by a 3-layer back propagation neural network (NN). The NN prediction rate achieved was 98% and the test data (37.7% of all data) was recognised correctly. Successful clustering of bacterial classes was also achieved by discriminant analysis (DA) of a normalised subset of sensor data. Cross-validation identified correctly seven unknown samples. In the second series of experiments after 150 min of microaerobic growth at 37 degreesC, 24 volatile samples were collected over the headspace of H. pylori cultures in enriched (HPP) and normal (HP) media and 11 samples over sterile (N) cultures. Forty-eight sensor parameters were extracted from 12 sensor responses and analysed by a 3-layer NN previously optimised by a genetic algorithm (GA). GA-NN analysis achieved a 94% prediction rate or unknown data. Additionally the genetically selected 16 input neurones were used to perform DA-cross validation that showed a clear clustering of three groups and reclassified correctly nine sniffs. It is concluded that the most important factors that govern the performance of an intelligent bacterial odour detection system are: (a) an odour generation mechanism, (b) a rapid odour delivery system similar to the mammalian olfactory system, (c) a gas sensor array of high reproducibility and (d) a hybrid intelligent model (expert system) which will enable the parallel use of GA-NNs and multivariate techniques. (C) 1999 Elsevier Science S.A. All rights reserved.

  • 202.
    Pavlou, AK
    et al.
    Cranfield University, Postgrad Med Sch, Bedford MK43 0AL, England; Cranfield University, Institute Biosci and Technology, Silsoe, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Sniffing out the truth: Clinical diagnosis using the electronic nose2000Inngår i: Clinical Chemistry and Laboratory Medicine, ISSN 1434-6621, E-ISSN 1437-4331, Vol. 38, nr 2, s. 99-112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recently the use of smell in clinical diagnosis has been rediscovered due to major advances in odour sensing technology and artificial intelligence (AI). It was well known in the past that a number of infectious or metabolic diseases could liberate specific odours characteristic of the disease stage. Later chromatographic techniques identified an enormous number of volatiles in human clinical specimens that might serve as potential disease markers. "Artificial nose" technology has been employed in several areas of medical diagnosis, including rapid detection of tuberculosis (TB), Helicobacter pylori (HP) and urinary tract infections (UTI). Preliminary results have demonstrated the possibility of identifying and characterising microbial pathogens in clinical specimens. A hybrid intelligent model of four interdependent "tools", odour generation "kits", rapid volatile delivery and recovery systems, consistent low drift sensor performance and a hybrid intelligent system of parallel neural networks (NN) and expert systems, have been applied in gastric, pulmonary and urine diagnosis. Initial clinical tests have shown that it may be possible in the near future to use electronic nose technology not only for the rapid detection of diseases such as peptic ulceration, UTI, and TB but also for the continuous dynamic monitoring of disease stages. Major advances in information and gas sensor technology could enhance the diagnostic power of future bio-electronic noses and facilitate global surveillance models of disease control and management.

  • 203.
    Pavlou, Alexandros K.
    et al.
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Magan, Naresh
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Jones, Jeff Meecham
    Public Health Laboratory Service, Gloucestershire Royal Hospital, Gloucester, UK.
    Brown, Jonathan
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Klatser, Paul
    KIT Biomedical Research, Royal Tropical Institute, Amsterdam, The Netherlands.
    Turner, Anthony P.F.
    Cranfield University, UK.
    Detection of Mycobacterium tuberculosis (TB) in vitro and in situ using an electronic nose in combination with a neural network system2004Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 20, nr 3, s. 538-544Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The use of volatile production patterns produced by Mycobacterium tuberculosis and associated bacterial infections from sputum samples were examined in vitro and in situ using an electronic nose based on a 14 sensor conducting polymer array. In vitro, it was possible to successfully discriminate between M. tuberculosis (TB) and control media, and between M. tuberculosis and M. avium, M. scrofulaceum and Pseudomonas aeruginosa cultures in the stationary phase after 5-6 h incubation at 37degreesC based on 35 samples. Using neural network (NN) analysis and cross-validation it was possible to successfully identify 100% of the TB cultures from others. A second in vitro study with 61 samples all four groups were successfully discriminated with 14 of 15 unknowns within each of the four groups successfully identified using cross-validation and discriminant function analysis. Subsequently, lipase enzymes were added to 46 sputum samples directly obtained from patients and the head space analysed. Parallel measurements of bacterial contamination were also carried out for confirmation using agar media. NN analysis was carried out using some of the samples as a training set. Based on the NN and genetic algorithms of up to 10 generations it was possible to successfully cross-validate 9 of 10 unknown samples. PCA was able to discriminate between TB infection alone, the controls, M. avium, P. aeruginosa and a mixed infection. These findings will have significant implications for the development of rapid qualitative systems for screening of patient samples and clinical diagnosis of tuberculosis.

  • 204.
    Perez, FG
    et al.
    University Florence, Dipartimento Sanita Pubbl Epidemiol and Chim Analit, Florence, Italy; .
    Mascini, M
    University Florence, Dipartimento Sanita Pubbl Epidemiol and Chim Analit, Florence, Italy; .
    Tothill, IE
    University Florence, Dipartimento Sanita Pubbl Epidemiol and Chim Analit, Florence, Italy; .
    Turner, APF
    Cranfield University, UK.
    Immunomagnetic separation with mediated flow injection analysis amperometric detection of viable Escherichia coli O1571998Inngår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 70, nr 11, s. 2380-2386Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The coupling of an immunological separation (using immunomagnetic beads) with amperometric now injection analysis detection of viable bacteria is presented. Using a solution containing Escherichia coli O157, the electrochemical response with two different mediators [potassium hexacyanoferrate(III) and 2,6-dichlorophenolindophenol] was evaluated in the FIA system. Antibody-derivatized Dynabeads were used to selectively separate E. coli O157 from a matrix The kinetics and the capacity parameters regarding the attachment of bacteria to the immunobeads were studied. The immunomagnetic separation was then used in conjunction with electrochemical detection to measure the concentration of viable bacteria. A calibration curve of colony-forming units (du) against electrochemical response was obtained. The detection limit for this rapid microbiological method was 10(5) cfu mL(-1), and the complete assay was performed in 2 h. Some advantages over ELISA methods are the direct detection of viable cells (and not total bacterial load) and the need for only one antibody (not enzyme-labeled), thus making the assay faster (only one washing step is necessary) and less expensive.

  • 205.
    Perfezou, Maelle
    et al.
    Catalan Institute of Nanotechnology.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan.
    Merkoci, Arben
    Catalan Institute of Nanotechnology.
    Cancer detection using nanoparticle-based sensors2012Inngår i: Chemical Society Reviews, ISSN 0306-0012, E-ISSN 1460-4744, Vol. 41, nr 7, s. 2606-2622Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    This tutorial review surveys the latest achievements in the use of nanoparticles to detect cancer biomarkers and cancer cells with a focus on optical and electrochemical techniques. Nanoparticle based cancer diagnostics are becoming an increasingly relevant alternative to traditional techniques. Although some drawbacks exist in relation to the obtained sensitivity the use of nanoparticle-based sensors in biomarker detection or cancer cell detection offers some advantages in comparison to conventional methods. The developed techniques can be interesting and relevant for their use in point-of-care of cancer diagnostics. The methods can be of low cost and in addition easy to be incorporated into user-friendly sensing platforms.

  • 206.
    Pfeiffer, Dorothea
    et al.
    BST Bio Sensor Technology GmbH, Germany.
    Wollenberger, Ulla
    University of Potsdam Golm, Germany.
    Turner, Anthony P. F.
    Cranfield University, UK.
    Professor Frieder Scheller turns 602002Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 17, nr 11-12, s. 911-912Artikkel i tidsskrift (Annet vitenskapelig)
  • 207.
    Piletska, Elena
    et al.
    University of Leicester, UK.
    Chianella, Iva
    Cranfield University, Bedfordshire, UK.
    Turner, Anthony
    Cranfield University, Bedfordshire, UK.
    Takayama, Kazuya
    Nitto Denko Asia Technical Centre PTE Ltd., Synapse, Singapore.
    Thaveeprungsripornc, Visit
    Nitto Denko Asia Technical Centre PTE Ltd., Synapse, Singapore.
    Piletsky, Sergey
    University of Leicester, UK.
    Optical biosensors based on universal pH indicator as a reporter for quantification of clinically-relevant compounds2014Inngår i: Journal of the Chinese Advanced Materials Society, ISSN 2168-1031, Vol. 2, nr 2, s. 99-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It was shown that universal indicator, a blend of pH-sensitive dyes which changes colour from red to purple over broad pH value range, in combination with a disposable optical sensor chip, could be used for the monitoring of physiologically important compounds. Changes in the optical properties of pH-sensitive dyes in the presence of enzyme catalysed reactions allowed quick and sensitive evaluation of the concentration of clinically important analytes such as glucose and urea. It was shown that the proposed optical biosensor could provide a sensitive and inexpensive method for the quantification of urea in plasma over a concentration range of 5–50 mM and glucose in the concentration range 1–25 mM. The system provides a generic platform that can be combined with other appropriate enzymes for the quantification of a range of physiological compounds to furnish versatile and portable clinical multisensors.

  • 208.
    Piletska, Elena V.
    et al.
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Piletsky, Sergey
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Terpetschnig, Ewald
    Institute of BioScience and Technology, Cranfield Centre for Analytical Science, Cranfield University, Cranfield, Bedfordshire, UK.
    Turner, Anthony
    Cranfield University, UK.
    Biotin-specific synthetic receptors prepared using molecular imprinting2004Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 504, nr 1, s. 179-183Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The composition of new molecularly imprinted polymers (MIPs) specific for biotin was optimised using molecular modelling software. Three functional monomers: methacrylic acid (MAA), 2-(trifluoromethyl)acrylic acid (TFAA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPSA), which demonstrated the highest binding scores with biotin, were tested on their ability to generate specific binding sites. The imprinted polymers were photografted to the surface of polystyrene microspheres in water. The affinity of the synthetic "receptor" sites was evaluated in binding experiments using horseradish peroxidase-labelled biotin. Good correlation was found between the modelling results and the performance of the materials in the template re-binding study. The dissociation constants for all MIPs were 1.4-16.8 nM, which is sufficient for most analytical applications where biotin is used as a label.

  • 209.
    Piletska, Elena V.
    et al.
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Romero-Guerra, Maria
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Chianella, Iva
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Turner, Anthony P.F.
    Cranfield University, UK.
    Piletsky, Sergey A.
    Institute of BioScience and Technology, Cranfield University, Silsoe, Bedfordshire, UK.
    Towards the development of multisensor for drugs of abuse based on molecular imprinted polymers2005Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 542, nr 1, s. 111-117Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The synthetic receptors for cocaine, deoxyephedrine, methadone and morphine were computationally designed and produced using molecular imprinting. The structure and energy of the molecular complexes were analysed by computational techniques. The possible structures of the binding sites in the synthetic receptors have been compared with those of corresponding natural receptors. The composition of imprinted polymers was optimised to allow adequate performance under the same experimental conditions. All selected molecular imprinting polymers (MIPs) demonstrated stronger affinity in comparison with corresponding blank polymers resulting in imprinted factors (1) equal to 1.2 (cocaine), 2.5 (deoxyephedrine), 3.5 (methadone) and 3 (morphine) which suggested that the specific binding site for each molecule was successfully created. The polymers studied possessed good selectivity and affinity towards their templates and could be recommended for the integration with sensor devices. From a practical point of view, especially for multisensor requirements, the synthetic receptors based on imprinted polymers could be superior to natural receptors due to their stability, robustness and compatibility with automation processes required for sensor fabrication.

  • 210.
    Piletska, EV
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Piletsky, SA
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Subrahmanyam, S
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    A new reactive polymer suitable for covalent immobilisation and monitoring of primary amines2001Inngår i: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 42, nr 8, s. 3603-3608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new polymer capable of reacting with primary amines was synthesised from allyl mercaptan, o-phthalic dialdehyde and ethylene glycol dimethacrylate by radical polymerisation. Reactive hemithioacetal formed by allyl mercaptan and dialdehyde can bind primary amino groups without additional pre-activation forming the fluorescent isoindole complex. It gives a great opportunity to monitor binding and perform loading of the amino compounds onto the reactive surface. The reactive polymer is found to be an effective matrix for immobilisation of the proteins and other amino-containing compounds in affinity chromatography and could be used for their detection in solution. (C) 2001 Elsevier Science Ltd. All rights reserved.

  • 211.
    Piletska, EV
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Romero-Guerra, M
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Guerreiro, AR
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Piletsky, SA
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Adaptation of the molecular imprinted polymers towards polar environment2005Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 542, nr 1, s. 47-51Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new simple method for the post-polymerisation treatment of molecularly imprinted polymers was proposed. A layer of mineral oil was deposited onto the surface of the polymer in order to create a hydrophobic environment in the binding sites and to improve the recognition properties of the polymer in polar solvents. The testing of polymers performed in acetonitrile showed that the modified polymers possessed significantly increased selectivity as compared with non-treated ones. The three-fold improvement of recognition of the template (cocaine) was achieved; the same time, for non-specific molecule (morphine) the improvement was only 1.3 times. The investigation of the stability of mineral oil coating on the polymer surface suggested that the effect produced is stable over a long period of time. This approach could be used to broaden the range of experimental conditions where molecularly imprinted polymers can perform successfully. (c) 2005 Elsevier B.V. All rights reserved.

  • 212.
    Piletska, EV
    et al.
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, NW
    Cranfield University, UK.
    Turner, APF
    Cranfield University, UK.
    Piletsky, SA
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Controlled release of the herbicide simazine from computationally designed molecularly imprinted polymers2005Inngår i: Journal of Controlled Release, ISSN 0168-3659, E-ISSN 1873-4995, Vol. 108, nr 1, s. 132-139Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The present study describes the development of materials suitable for environmental control of algae. Molecularly imprinted polymers (MIPs) were used as simazine carriers able to provide the controlled release of simazine into water. Three polymers were designed using computational modelling. The selection of methaerylic acid (MA) and hydroxyethyl methacrylate (HEM) as functional monomers was based on results obtained using the Leapfrog algorithm. A cross-linked polymer made without functional monomers was also prepared and tested as a control. The release of simazine from all three polymers was studied. It was shown that the presence of functional monomers is important for polymer affinity and for controlled release of herbicide. The speed of release of herbicide correlated with the calculated binding characteristics. The high-affinity MA-based polymer released similar to 2% and the low-affinity HEM-based polymer released similar to 27% of the template over 25 days. The kinetics of simazine release from HEM-based polymer show that total saturation of an aqueous environment could be achieved over a period of 3 weeks and this corresponds to the maximal simazine solubility in water. The possible use of these types of polymers in the field of controlled release is discussed. (c) 2005 Elsevier B.V. All rights reserved.

  • 213.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Alcock, S
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Molecular imprinting: at the edge of the third millennium2001Inngår i: Trends in Biotechnology, ISSN 0167-7799, E-ISSN 1879-3096, Vol. 19, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Molecularly imprinted polymers (MIPs) represent a new class of materials that have artificially created receptor structures(1-3). Since their discovery in 1972, MIPs have attracted considerable interest from scientists and engineers involved with the development of chromatographic adsorbents, membranes, sensors and enzyme and receptor mimics.

  • 214.
    Piletsky, SA
    et al.
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Guerreiro, A
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Piletska, EV
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Chianella, I
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Karim, K
    Cranfield University, Institute BioScience and Technology, Bedford MK45 4DT, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery. 2. Influence of polymerization pressure and polymer swelling on the performance of molecularly imprinted polymers2004Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 37, nr 13, s. 5018-5022Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers was imprinted with (+)-ephedrine at ambient and 10 bar pressure. The performance of the synthesized materials was studied by HPLC at six different temperatures: 0, 10, 20, 30, 40, and 50 degreesC. It was shown that the polymer morphology (surface area and porosity) and enantioselective properties are different for these two polymers-an unexpected result which was in contradiction with the theoretical forecasts. A possible mechanism which explains the observed phenomenon is discussed. The contributing factor which influenced the polymer performance was the polymer swelling. This shows that, in addition to temperature, other physical parameters such as pressure and polymer swelling should be analyzed and accounted for in the quality control of MIP synthesis and application.

  • 215.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Day, CJ
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Freebairn, KW
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Legge, C
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; Glaxo Wellcome Research and Dev Ltd, Stevenage SG1 2NY, Herts, England; .
    Turner, APF
    Cranfield University, UK.
    Recognition of ephedrine enantiomers by molecularly imprinted polymers designed using a computational approach2001Inngår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 126, nr 10, s. 1826-1830Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new approach to the computational design of molecularly imprinted polymers (MIP) specific for ephedrine is presented. A virtual library of functional monomers was developed and screened against the template using molecular modelling software. The monomers giving the highest binding score were co-polymerized with a cross-linker in the presence of ephedrine. Control (blank) polymers were prepared under the same conditions but in the absence of the template. A good correlation was found between the modelling results and performance of the materials in an HPLC study. A MIP based on one of the selected monomers-hydroxyethyl methacrylate-gave a separation of ephedrine enantiomers with a separation factor a of 1.42-2.09 (depending on temperature). This figure is larger than the a values generally obtained with commercially available chiral phases. It is anticipated that the computational approach will be of use for the rational design of MIPS and the prediction of polymer affinity and specificity.

  • 216.
    Piletsky, SA
    et al.
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Kurys, YI
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Panasyuk, TL
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Goumenyuk, A
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Sergeeva, TA
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Karim, K
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Piletska, EV
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Elskaya, AV
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; Ukrainian Acad Science, LV Pisarzhevsky Phys Chemistry Institute, UA-03039 Kiev, Ukraine; Institute Mol Biol and Genet, UA-252143 Kiev, Ukraine; .
    Turner, APF
    Cranfield University, UK.
    Preparation and use of membranes with potential-controlled functions2001Inngår i: Instrumentation Science & Technology, ISSN 1073-9149, E-ISSN 1525-6030, Vol. 29, nr 5, s. 383-391Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new type of membrane with potential-controllable functions was prepared by grafting polyaniline to the surface of track-etch Nucleopore membrane with a vacuum deposited gold layer (PANI-membranes). Because of the cylindrical shape of these pores, a nanocylinder of the desired conducting material is obtained in each pore. A potential applied to PANI-membranes governs the properties of the conducting layer, such as charge and its distribution, conformation, and density and, hence, controls the diffusion rate of substances through these membranes. The variation in diffusion rates of different substances with different potentials applied to PANI-membranes provides the basis for the application of these membranes in separation processes and sensors.

  • 217.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Mijangos, I
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Guerreiro, A
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Chianella, I
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery: Influence of polymerization time and different initiation conditions on performance of molecularly imprinted polymers2005Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 38, nr 4, s. 1410-1414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers was imprinted with (-)-ephedrine using thermal and UV initiation. The performance of the synthesized materials was studied by HPLC. It was shown that the polymer morphology and enantioselective properties are dependent on the polymerization conditions and time of the reaction. The binding mechanism of synthesized polymers was studied using Vant Hoff analysis. The results of testing strongly indicate that the polymer receptor structure is shaped during the initial phase of polymer gelation. The present study shows the importance of controlling experimental conditions in the MIP synthesis and highlights potential problems expected during scaling up of MIP production.

  • 218.
    Piletsky, SA
    et al.
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Piletska, EV
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Bossi, A
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Lowe, P
    Cranfield University, Institute BioScience and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Substitution of antibodies and receptors with molecularly imprinted polymers in enzyme-linked and fluorescent assays2001Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 16, nr 12-sep, s. 701-707Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new technique for coating microtitre plates with molecularly imprinted polymers (MIP), specific for low-molecular weight analytes (epinephrine, atrazine) and proteins is presented. Oxidative polymerization was performed in the presence of template; monomers: 3-aminophenylboronic acid (APBA), 3-thiopheneboronic acid (TBA) and aniline were polymerized in water and the polymers were grafted onto the polystyrene surface of the microplates. It was found that this process results in the creation of synthetic materials with antibody-like binding properties. It was shown that the MIP-coated microplates are particularly useful for assay development. The high stability of the polymers and good reproducibility of the measurements make MIP coating an attractive alternative to conventional antibodies or receptors used in enzyme linked immunosorbent assay (ELISA). (C) 2001 Elsevier Science B.V. All rights reserved.

  • 219.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Chen, BN
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Weston, D
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Barrett, G
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Lowe, P
    Cranfield University, Institute Biosci and Technology, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Chemical grafting of molecularly imprinted homopolymers to the surface of microplates. Application of artificial adrenergic receptor in enzyme-linked assay for beta-agonists determination2000Inngår i: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 72, nr 18, s. 4381-4385Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A technique for coating of microplate weds with a molecularly imprinted polymer (MTP), specific for epinephrine, is presented. 3-Aminophenylboronic acid was polymerized in the presence of epinephrine using oxidation of the monomer by ammonium persulfate. This process resulted in the grafting of a thin polymer layer onto the polystyrene surface of the microplates. The polymer affinity was determined by an enzyme-linked assay using a conjugate of horseradish peroxidase and norepinephrine (HRP-N). It was found that imprinting resulted in increased affinity of the polymer toward HRP-N and epinephrine. Influence of the buffer pH and concentration on the polymer affinity was analyzed. It was shown that the MIP-coated microplates could be used for assay development and drug screening. The high stability of the polymers and good reproducibility of the measurements make MIP coating an attractive alternative to traditional antibodies or receptors, used in ELISA.

  • 220.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Davis, F
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Higson, SPJ
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Photochemical polymerization of thiophene derivatives in aqueous solution2004Inngår i: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, nr 19, s. 2222-2223Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel method of photochemical polymerization of thiophene derivatives in aqueous solution catalyzed by potassium dichromate and initiated by illumination is described.

  • 221.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Piletska, EV
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Karim, K
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Freebairn, KW
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Legge, CH
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; GlaxoSmithKline Research and Dev, Stevenage SG1 2NY, Herts, England; .
    Turner, APF
    Cranfield University, UK.
    Polymer cookery: Influence of polymerization conditions on the performance of molecularly imprinted polymers2002Inngår i: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 35, nr 19, s. 7499-7504Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers has been imprinted with (-)-ephedrine at six different temperatures, ranging from -30 to +80 degreesC. Polymer affinity and specificity were observed to be strongly dependent on the polymerization temperature. The experimental results suggest that the polymer is able to "memorize" the temperature used in the polymerization process in a manner similar to previously documented MIP "memory" effects for the template and polymerization solvent. In a study of the effect of temperature on retention and selectivity in HPLC (using the MIP as a column packing), a clear gradient change in the Vant Hoff plots was observed at 20-30 degreesC. This indicates a transition in binding mechanism from exothermic at higher temperatures to endothermic at lower temperatures. These results, supported by the evidence of template-induced MIP swelling, are interpreted in terms of desolvation and conformational changes in the polymers induced by the interaction with the template.

  • 222.
    Piletsky, SA
    et al.
    Cranfield University, Institute Biosci and Technology, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Electrochemical sensors based on molecularly imprinted polymers2002Inngår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 14, nr 5, s. 317-323Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Over the past two decades, molecularly imprinted polymers (MIPs) have attracted broad interest from scientists engaged in sensor development. This attention can be explained by the serious potential advantages of using MIPs in pi ace of natural receptors and enzymes such as their superior stability, low cost and easy preparation. This review encompasses recent achievements in molecular imprinting related to the area of sensor technology. Since electrochemical biosensors dominate the market and due to specific requirements of this journal, the emphasis of this review will be on the development of electrochemical MIP sensors. The problems associated with application of imprinted polymers in sensors are highlighted and possible solutions indicated. The commercial potential of MIP-based sensors is analyzed in the expectation that they can offer improved performance in the analytical market place.

  • 223.
    Piletsky, Sergey
    et al.
    Institute of BioScience and Technology, Cranfield University at Silsoe, Bedfordshire, UK.
    Piletska, Elena
    Institute of BioScience and Technology, Cranfield University at Silsoe, Bedfordshire, UK.
    Bossi, Alessandra
    Deparment of Science and Technology, University of Verona, Verona, Italy.
    Turner, Nicholas
    Institute of BioScience and Technology, Cranfield University at Silsoe, Bedfordshire, UK.
    Turner, Anthony
    Cranfield University, UK.
    Surface functionalization of porous polypropylene membranes with polyaniline for protein immobilization2003Inngår i: Biotechnology and Bioengineering, ISSN 0006-3592, E-ISSN 1097-0290, Vol. 82, nr 1, s. 86-92Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Commercial porous polypropylene membranes were chemically modified with polyaniline (PANI) using ammonium persulfate as the oxidizer. The influence of polymerization conditions on the membrane properties was studied by adsorption analysis and membrane permeability. The PANI-coated polypropylene (PANI/PP) membranes possessed high affinity toward the proteins, which can be immobilized onto the membrane surface through physical adsorption or covalent immobilization. The quantity of immobilized horseradish peroxidase (HRP) and its activity depended on the quantity and quality (oxidation level) of PANI. The storage conditions for PANI/PP membranes containing immobilized HRP were studied. HRP immobilized on the PANI/PP membrane was shown to retain 70% of its activity after 3-month storage at +5degreesC, suggesting that this material can be used for practical application, such as in bioreactors as enzyme membranes.

  • 224.
    Piletsky, Sergey
    et al.
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Piletska, Elena
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Karim, Kal
    Institute of BioScience and Technology, Cranfield University, Bedfordshire, UK.
    Foster, Graham
    GlaxoSmithKline Research and Development, Stevenage, Herts, UK.
    Legge, Colton
    GlaxoSmithKline Research and Development, Stevenage, Herts, UK.
    Turner, Anthony
    Cranfield University, UK.
    Custom synthesis of molecular imprinted polymers for biotechnological application - Preparation of a polymer selective for tylosin2004Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 504, nr 1, s. 123-130Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A molecularly imprinted polymer (MIP) selective for tylosin was designed and synthesised using a computational method (MIP "dialling"). In re-binding experiments the MIP demonstrated high affinity for tylosin in aqueous solutions and in organic solvents. The synthesised polymer was tested for re-binding with the template and related metabolites such as tylactone, narbomycin and picromycin. The HPLC analysis showed that the computationally designed polymer is specific and capable of separating the template from its structural analogues. The MIP was capable of recovering tylosin from broth samples. The polymer capacity for tylosin was estimated as 6.4 mg/g for MIP, which was suitable for practical application and tylosin recovery from broth samples. Among the advantages of this was the possibility to adsorb tylosin from a complex media with easy removal of oils and other impurities which are present in significant quantities, which can create problems for its chromatographic purification procedure. The MIP "dialling" procedure can have a general significance for the fast preparation of specific adsorbents for biotechnological applications.

  • 225.
    Poma, Alessandro
    et al.
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    P. F. Turner, Anthony
    Cranfield University, UK.
    A. Piletsky, Sergey
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    Advances in the manufacture of MIP nanoparticles2010Inngår i: Trends in Biotechnology, ISSN 0167-7799, E-ISSN 1879-3096, Vol. 28, nr 12, s. 629-637Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Molecularly imprinted polymers (MIPs) are prepared by creating a three-dimensional polymeric matrix around a template molecule After the matrix is removed, complementary cavities with respect to shape and functional groups remain MIPs have been produced for applications in in vitro diagnostics, therapeutics and separations However, this promising technology still lacks widespread application because of issues related to large-scale production and optimization of the synthesis Recent developments in the area of MIP nanoparticles might offer solutions to several problems associated with performance and application This review discusses various approaches used in the preparation of MIP nanoparticles, focusing in particular on the issues associated with large-scale manufacture and implications for the performance of synthesized nanomaterials

  • 226.
    Psoma, Sotiria D.
    et al.
    Cranfield University, Cranfield Health, Cranfield, Bedfordshire, UK.
    D. van der Wal, Peter
    EPFL, IMT-SAMLAB, Switzerland.
    Frey, Olivier
    EPFL, IMT-SAMLAB, Switzerland.
    de Rooij, Nicolaas F.
    EPFL, IMT-SAMLAB, Switzerland.
    Turner, Anthony P. F.
    Cranfield University, UK.
    A novel enzyme entrapment in SU-8 microfabricated films for glucose micro-biosensors2010Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 26, nr 4, s. 1582-1587Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The present work investigates the utilisation of the widely used SU-8 photoresist as an immobilisation matrix for glucose oxidase (GOx) for the development of glucose micro-biosensors. The strong advantage of the proposed approach is the simultaneous enzyme entrapment during the microfabrication process within a single step, which is of high importance for the simplification of the BioMEMS procedures. Successful encapsulation of the enzyme GOx in "customised" SU-8 microfabricated structures was achieved through optimisation of the one-step microfabrication process. Although the process involved contact with organic solvents, UV-light exposure, heating for pre- and post-bake and enzyme entrapment in a hard and rigid epoxy resin matrix, the enzyme retained its activity after encapsulation in SU-8. Measurements of the immobilised enzymes activity inside the SU-8 matrix were carried out using amperometric detection of hydrogen peroxide in a 3-electrode setup. Films without enzyme showed negligible variation in current upon the addition of glucose, as opposed to films with encapsulated enzyme which showed a very clear increase in current. Experiments using films of increased thickness or enzyme concentration, showed a higher response, thus proving that the enzyme remained active not only on the films surface, but also inside the matrix as well. The proposed enzyme immobilisation in SU-8 films opens up new possibilities for combining BioMEMS with biosensors and organic electronics.

  • 227.
    R. Guerreiro, Antonio
    et al.
    Cranfield University, Silsoe MK45 4DT, Beds, England.
    Korkhov, Vadim
    Latvian State University, Institute Polymer Mat, LV-1006 Riga, Latvia.
    Mijangos, Irene
    Cranfield University, Silsoe MK45 4DT, Beds, England.
    V. Piletska, Elena
    Cranfield University, Silsoe MK45 4DT, Beds, England.
    Rodins, Juris
    Latvian State University, Institute Polymer Mat, LV-1006 Riga, Latvia.
    P. F. Turner, Anthony
    Cranfield University, UK.
    A. Piletsky, Sergey
    Cranfield University, Silsoe MK45 4DT, Beds, England.
    Influence of continuous magnetic field on the separation of ephedrine enantiomers by molecularly imprinted polymers2008Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 23, nr 7, s. 1189-1194Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A set of polymers was imprinted with (-)-ephedrine using UV initiation, under the influence of a constant external magnetic field with intensities ranging from 0 to 1.55T Synthesised materials were characterised by X-ray crystallography, infrared spectroscopy, swelling and surface area. Recognition properties were assessed by the ability to discriminate between (+) and (-)-ephedrine and by Scatchard analyses on chromatographic mode. It was shown that polymer morphology and recognition properties are affected by the magnetic field. This resulted in considerable improvements in the chromatographic resolution of ephedrine enantiomers by materials synthesised under the influence of magnetic field. Apparently the magnetic field improved the ordering of the polymer structure and facilitated the formation of more uniform imprinting sites. (c) 2007 Elsevier B.V. All rights reserved.

  • 228.
    RAMSAY, G
    et al.
    CRANFIELD INST TECHNOL,CTR BIOTECHNOL,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    DEVELOPMENT OF AN ELECTROCHEMICAL METHOD FOR THE RAPID-DETERMINATION OF MICROBIAL CONCENTRATION AND EVIDENCE FOR THE REACTION-MECHANISM1988Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 215, nr 02-jan, s. 61-69Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 229.
    Rasinger, JD
    et al.
    University Florence, Department Chemistry, I-50019 Florence, Italy; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Marrazza, G
    University Florence, Department Chemistry, I-50019 Florence, Italy; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Briganti, F
    University Florence, Department Chemistry, I-50019 Florence, Italy; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Scozzafava, A
    University Florence, Department Chemistry, I-50019 Florence, Italy; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Mascini, M
    University Florence, Department Chemistry, I-50019 Florence, Italy; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Evaluation of an FIA operated amperometric bacterial biosensor, based on pseudomonas putida F1 for the detection of benzene, toluene, ethylbenzene, and xylenes (BTEX)2005Inngår i: Analytical Letters, ISSN 0003-2719, E-ISSN 1532-236X, Vol. 38, nr 10, s. 1531-1547Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Recently, the development and optimization of a flow injection analysis (FIA) operated bacterial biosensor based on the aerobic catabolism of Pseudomonas putida ML2 was reported in the literature (Lanyon et al. 2004, 2005). By adapting information from these reports, we investigated whether operating parameters and procedures of the benzene biosensor could be directly applied to a new system based on a different bacterial strain for the detection of the whole benzene, toluene, ethylbenzene, and xylenes range. Cells of the investigated bacterial strain, Pseudomonas putida F1, were immobilized between two cellulose acetate membranes and fixed onto a Clark dissolved oxygen electrode. The P. putida F1 aerobically degrades benzene, toluene, and ethylbenzene (BTE) (Cho et al. 2000). The BTE biosensor in kinetic mode FIA displayed a linear range of 0.02-0.14 mM benzene (response time: 5 min, baseline recovery time: 15 min), 0.05-0.2 mM toluene (response time: 8 min, baseline recovery time: 20 min), and 0.1-0.2 mM ethylbenzene (response time: 12 min, baseline recovery time: 30 min), respectively. Due to the differences in sensitivity, response, and baseline recovery times for BTE, it was possible to differentiate each compound in mixtures of these volatile organic compounds (VOCs). No response for xylenes could be obtained since they cannot be completely metabolized by this bacterial strain. However, it was reported that the range of compounds degradable by P. putida F1 can possibly be expanded by cultivating the cells on different carbon sources (Choi et al. 2003). The sensor showed good intra- and interassay reproducibility, and all obtained results were comparable with those reported in the literature. The demonstrated reproducibility and the simplicity and ease of use as well as the portability for in situ measurements indicates that the biosensor could be suitable as a reliable initial warning device for elevated BTE levels in indoor and outdoor environments.

  • 230.
    Ravichandran, Ranjithkumar
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Åstrand, C.
    KTH Royal Institute Technology, Sweden.
    Patra, Hirak Kumar
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Chotteau, V.
    KTH Royal Institute Technology, Sweden.
    Phopase, Jaywant
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Intelligent ECM mimetic injectable scaffolds based on functional collagen building blocks for tissue engineering and biomedical applications2017Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, nr 34, s. 21068-21078Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hydrogels comprising natural extracellular matrix (ECM) components are very attractive as scaffolds for regenerative medicine applications due to their inherent biointeractive properties. Responsive materials that adapt to their surrounding environments and regulate transport of ions and bioactive molecules manifest significant advantages for biomedical applications. Although there are many exciting challenges, the opportunity to design, fabricate and engineer stimuli-responsive polymeric systems based on ECM components is particularly attractive for regenerative medicine. Here we describe a one-pot approach to fabricate in situ fast gellable intelligent ECM mimetic scaffolds, based on methacrylated collagen building blocks with mechanical properties that can be modulated in the kPa-MPa range and that are suitable for both soft and hard tissues. Physiochemical characterizations demonstrate their temperature and pH responsiveness, together with the structural and enzymatic resistance that make them suitable scaffolds for long-term use in regenerative medicine and biomedical applications. The multifunctionality of these hydrogels has been demonstrated as an in situ depot-forming delivery platform for the adjustable controlled release of proteins and small drug molecules under physiological conditions and as a structural support for adhesion, proliferation and metabolic activities of human cells. The results presented herein should be useful to the design and fabrication of tailor-made scaffolds with tunable properties that retain and exhibit sustained release of growth factors for promoting tissue regeneration.

  • 231.
    Ravichandran, Ranjithkumar
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Martinez Gil, Jose Gabriel
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Jager, Edwin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Phopase, Jaywant
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska fakulteten.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Type I Collagen-Derived Injectable Conductive Hydrogel Scaffolds as Glucose Sensors2018Inngår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 19, s. 16244-16249Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The advent of home blood glucose monitoring revolutionized diabetes management, and the recent introduction of both wearable devices and closed-loop continuous systems has enormously impacted the lives of people with diabetes. We describe the first fully injectable soft electrochemical glucose sensor for in situ monitoring. Collagen, the main component of a native extracellular matrix in humans and animals, was used to fabricate an in situ gellable self-supporting electroconductive hydrogel that can be injected onto an electrode surface or into porcine meat to detect glucose amperometrically. The study provides a proof-of-principle of an injectable electrochemical sensor suitable for monitoring tissue glucose levels that may, with further development, prove clinically useful in the future.

  • 232.
    Rawat, Niharika
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Mishra, Prashant
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Ashaduzzaman, Md
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Yazdi, R
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Syväjärvi, Michael
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Halvledarmaterial. Linköpings universitet, Tekniska fakulteten.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Tiwari, Ashutosh
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten. Tekidag AB UCS Mjärdevi Science Park, Sweden.
    Fabrication of an atom-thick graphene bioanode for biofuel cell applications2016Inngår i: Biosensors 2016 – The World Congress on Biosensors, Gothenburg, Sweden, 25-27 May 2016, Elsevier, 2016Konferansepaper (Annet vitenskapelig)
  • 233.
    RAWSON, DM
    et al.
    CRANFIELD INST TECHNOL,CTR CEREBROVASC,DIV BIOELECTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    WILLMER, AJ
    CRANFIELD INST TECHNOL,CTR CEREBROVASC,DIV BIOELECTR,CRANFIELD MK43 0AL,BEDS,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    WHOLE-CELL BIOSENORS FOR ENVIRONMENTAL MONITORING1989Inngår i: BIOSENSORS, ISSN 0265-928X, Vol. 4, nr 5, s. 299-311Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 234.
    Renneberg, Reinhard
    et al.
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Pfeiffer, Dorothea
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Lisdat, Fred
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Wilson, George
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Wollenberger, lla
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Ligler, Frances
    University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
    Turner, Anthony P. F.
    Cranfield University, UK.
    Frieder scheller and the short history of biosensors2008Inngår i: Advances in Biochemical Engineering/Biotechnology, ISSN 0724-6145, E-ISSN 1616-8542, Vol. 109, s. 1-18Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    This is a first attempt at a brief sketch of the history of biosensors. It is far from complete and rather unsystematic. Many names are still missing, and we apologize for this. But the authors hope to have laid a humble cornerstone for a future "Complete History of Biosensors". We hope that many of our colleagues will contribute!

  • 235.
    Rezaei, Babak
    et al.
    Amirkabir Univ Technol, Iran.
    Shoushtari, Ahmad Mousavi
    Amirkabir Univ Technol, Iran.
    Rabiee, Mohammad
    Amirkabir Univ Technol, Iran.
    Uzun, Lokman
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten. Hacettepe Univ, Turkey.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Electrochemical performance of nanofibrous highly flexible electrodes enhanced by different structural configurations2018Inngår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 155, s. 81-90Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to their unique physicomechanical properties, one dimensional (1D) nanostructured conductive materials offer remarkable potential as a flexible electroactive medium for developing miniaturized electronic devices such as supercapacitors, sensors and actuators. In this work, thin films composed of nanocomposite nanofibers with two different architectures, i.e. whiskered nanofibers (WNFs) and hierarchical-structured nanofibers (H-SNFs), were fabricated and their capability to serve as flexible and bendable electrodes were evaluated. The main difference of these two architectures is how the distributions of the nano-fillers (carboxylated multiwalled carbon nanotubes, CMWCNTs) through the nanofibers, i.e. the isotropic and anisotropic arrangements, lead to WNFs and H-SNFs, respectively. The percolation threshold of conduction for the H-SNFs (composed of 0.5 wt% CMWCNTs) and the WNFs (composed of 5 wt% CMWCNTs) were 0.13 S cm(-1) and 0.07 S cm(-1), respectively. Moreover, according to the electrochemical characterizations, although the WNFs had ten orders of magnitude higher nanotube content, the electroactivity and electron transfer rate of H-SNFs was considerably higher than those of WNFs, so that the cyclic voltammetric peak currents of H-SNFs was approximately 1.6 times higher than that of WNFs. As a proof-of-concept, our results indicate that the structural configuration is a major determinative factor, which can largely dictate the final electrical and electrochemical properties of the nanocomposite nanofibers. The bending durability results showed good electrochemical performance even upon 100 bending cycles with 120 bending angles (retained 93.4% and 83.3% of the initial peak currents for H-SNFs and WNFs, respectively). These two flexible nanocomposite nanofibrous structures could be promising materials for the development of flexible electrodes for biosensing to energy storage applications. (C) 2017 Elsevier Ltd. All rights reserved.

    Fulltekst tilgjengelig fra 2019-12-02 15:53
  • 236.
    Rezaei, Babak
    et al.
    Nanotechnology Institute, Amirkabir University of Technology, Tehran, Iran.
    Shoushtari, Ahmad Mousavi
    Textile Engineering Department, AmirKabir University of Technology, Tehran, Iran.
    Rabiee, Mohammad
    Biomaterials Group, Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
    Uzun, Lokman
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska fakulteten.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Mak, Wing Cheung
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Multifactorial modeling and optimization of solution and electrospinning parameters to generate superfine polystyrene nanofibers2018Inngår i: Advances in Polymer Technology, ISSN 0730-6679, E-ISSN 1098-2329, Vol. 37, nr 8, s. 2743-2755Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study was conducted to provide a quantitative understanding of the influence of the different solution and electrospinning variables on the morphology and the mean diameter of electrospun polystyrene nanofibers. In this regard, the effect of different solvents and ionic additives on the electrical conductivity, viscosity, and surface tension of the electrospinning solutions and thereby the morphology of nanofibers were examined. The results indicated that the morphology of the fibers is extremely dependent on the solvent’s properties, especially volatility and electrical conductivity, and the ionic characteristics of additives. Finally, to estimate the optimal electrospinning conditions for production of nanofibers with minimum possible diameter, modeling of the process was undertaken using the response surface methodology. Experimentally, nanofibers with the finest diameter of 169 ï¿œ 21 nm were obtained under the optimized conditions, and these could be considered promising candidates for a wide practical range of applications ranging from biosensors to filtration.

  • 237.
    Rezaei, Babak
    et al.
    Nanotechnology Institute, Amirkabir University of Technology, Tehran, Iran.
    Shoushtari, Ahmad Mousavi
    Textile Engineering Department, AmirKabir University of Technology, Tehran, Iran.
    Rabiee, Mohammad
    Biomaterials Group, Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
    Uzun, Lokman
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    Wing Cheung, Mak
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    TURNER, APF
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensor- och aktuatorsystem. Linköpings universitet, Tekniska fakulteten.
    An electrochemical immunosensor for cardiac Troponin I using electrospun carboxylated multi-walled carbon nanotube-whiskered nanofibres2018Inngår i: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 182, s. 178-186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A sandwich-type nanostructured immunosensor based on carboxylated multi-walled carbon nanotube (CMWCNT)-embedded whiskered nanofibres (WNFs) was developed for detection of cardiac Troponin I (cTnI). WNFs were directly fabricated on glassy carbon electrodes (GCE) by removing the sacrificial component (polyethylene glycol, PEG) after electrospinning of polystyrene/CMWCNT/PEG nanocomposite nanofibres, and utilised as a transducer layer for enzyme-labeled amperometric immunoassay of cTnI. The whiskered segments of CMWCNTs were activated and utilised to immobilise anti-cTnT antibodies. It was observed that the anchored CMWCNTs within the nanofibres were suitably stabilised with excellent electrochemical repeatability. A sandwich-type immuno-complex was formed between cTnI and horseradish peroxidase-conjugated anti-cTnI (HRP-anti-cTnI). The amperometric responses of the immunosensor were studied using cyclic voltammetry (CV) through an enzymatic reaction between hydrogen peroxide and HRP conjugated to the secondary antibody. The nanostructured immunosensor delivered a wide detection range for cTnI from the clinical borderline for a normal person (0.5-2 ng mL(-1)) to the concentration present in myocardial infarction patients (amp;gt; 20 ng mL(-1)), with a detection limit of similar to 0.04 ng mL(-1). It also showed good reproducibility and repeatability for three different cTnI concentration (1, 10 and 25 ng mL(-1)) with satisfactory relative standard deviations (RSD). Hence, the proposed nanostructured immunosensor shows potential for point-of-care testing.

    Fulltekst tilgjengelig fra 2020-01-31 16:17
  • 238.
    Romero Guerra, Maria
    et al.
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    Chianella, Iva
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    V. Piletska, Elena
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    Karim, Kal
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    P. F. Turner, Anthony
    Cranfield University, UK.
    A. Piletsky, Sergey
    Cranfield University, Cranfield MK43 0AL, Beds, England.
    Development of a piezoelectric sensor for the detection of methamphetamine2009Inngår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 134, nr 8, s. 1565-1570Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A computationally designed molecularly imprinted polymer (MIP) specific for methamphetamine was used as a synthetic receptor for the development of a piezoelectric sensor. Several different protocols were tested for the immobilisation of the MIP onto the gold sensor surface. The developed MIP sensor had a detection limit for methamphetamine as low as 1 mu g mL(-1). The effect of the addition of poly(vinyl acetate) (PVA) on the pre-polymerisation mixtures, which increases the porosity of the polymer layer, was also studied using an Atomic Force Microscope (AFM). PVA seemed to affect both the porosity and the binding kinetics of the polymers prepared in dimethylformamide (DMF). However, no clear effect on porosity and binding kinetics was observed when polymers were prepared in diglyme. Moreover, PVA did not appear to improve the amplitude of the sensor response. In conclusion, because of its excellent recognition ability in aqueous solutions, the sensor described in this work could be an ideal starting point for the development of a commercial device for fast, on-site or road-side testing of drugs of abuse in body fluids such as saliva.

  • 239.
    Saeid Hejazi, Mohammad
    et al.
    Tabriz University of Medical Science, Iran; Tabriz University of Medical Science, Iran.
    Reza Majidi, Mir
    University of Tabriz, Iran.
    Gholizadeh, Sima
    University of Tabriz, Iran.
    Hamidi-Asl, Ezat
    Mazandaran University, Iran.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan.
    Mahdi Golabi, Seyed
    University of Tabriz, Iran.
    Effect of Electrophoresis on the Efficiency of Graphite-Nano-TiO2 Modified Silica Sol-Gel Electrode2015Inngår i: Journal of Nanoscience and Nanotechnology, ISSN 1533-4880, E-ISSN 1533-4899, Vol. 15, nr 5, s. 3405-3410Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrophoresis treatment was used to improve the function of a nano-TiO2 modified sol-gel electrode. Electrodes were prepared using TiO2 nanoparticles and fine graphite powder and then treated by electrophoresis. The developed electrode was employed for the detection of lactate dehydrogenase (LDH) by following the decrease in the immobilised lactate peak current due to its LDH-mediated enzymatic oxidation. Detection was realised using square wave voltammetry (SWV). Experiments showed that the positive and negative heads of the electrophoresis-treated electrode displayed different activities, with the positive head response being remarkably improved. Parameters affecting the electrode response, such as applied potential value, electrophoresis time and percentage of TiO2, were investigated and optimised. The improved performance was dependent on TiO2 concentration as well as electrophoresis voltage and time. The prepared sensor, under optimised conditions, displayed a detection limit of 0.0073 U/mu l for LDH.

  • 240.
    Saha, Suparna
    et al.
    University of Calcutta, India.
    Sarkar, Priyabrata
    University of Calcutta, India.
    Turner, Anthony
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan.
    Interference-Free Electrochemical Detection of Nanomolar Dopamine Using Doped Polypyrrole and Silver Nanoparticles2014Inngår i: Electroanalysis, ISSN 1040-0397, E-ISSN 1521-4109, Vol. 26, nr 10, s. 2197-2206Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a new approach to detect dopamine in nanomolar range using an electrochemical sensor utilizing a composite made of chitosan-stabilized silver nanoparticles and p-toluene sulfonic acid-doped ultrathin polypyrrole film. Studies included cyclic voltammogram, amperometry, differential pulse voltammetry and also investigation by electrochemical impedance spectroscopy. A detection limit of 0.58 nM was achieved in the linear range 1 x 10(-9) M to 1.2 x 10(-7) M. High sensitivity towards DA, good reproducibility and long-term stability have been demonstrated without interference from ascorbic acid, uric acid, epinephrine, l-dopa, glucose. The sensing system was successfully applied for quantitative determination of dopamine in commercially available human blood serum.

  • 241.
    SAINI, S
    et al.
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    HALL, GF
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    DOWNS, MEA
    CRANFIELD BIOTECHNOL LTD,CRANFIELD MK43 0AL,BEDS,ENGLAND; LAB GOVT CHEMIST,SENSORS TECHNOL GRP,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    ORGANIC-PHASE ENZYME ELECTRODES1991Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 249, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Organic phase enzyme electrodes (OPEEs) offer new possibilities both for the design of biosensors for use in organic solvents and in the construction of devices incorporating an organic phase for use with aqueous samples. The advantages that accrue from performing biocatalytic and electrochemical reactions in non-aqueous systems are discussed in relation to possible applications in medicine. pharmaceuticals, petrochemicals, the food industry, environmental monitoring and defence. This critical but speculative review considers the detailed implications of operating enzyme electrodes in organic solvents and briefly examines the broader issues of optical, calorimetric and piezoelectric transduction coupled with both catalytic and affinity systems, such as nucleic acid probes and antibodies.

  • 242.
    SAINI, S
    et al.
    LAB GOVT CHEMIST,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    SURAREUNGCHAI, W
    LAB GOVT CHEMIST,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    TURNER, APF
    Cranfield University, UK.
    DOWNS, MEA
    LAB GOVT CHEMIST,TEDDINGTON TW11 0LY,MIDDX,ENGLAND; .
    PRELIMINARY INVESTIGATION OF A BIOELECTROCHEMICAL SENSOR FOR THE DETECTION OF PHENOL VAPORS1995Inngår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 10, nr 10-sep, s. 945-957Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This work investigates the feasibility of constructing a bioelectrochemical sensor that can operate directly in gases. A series of experiments are described, resulting in a sensor that is responsive to phenol vapours. The sensor was based on ionically conducting films that incorporate a biological redox catalyst at the surface of an array of interdigitated microband electrodes. Exposure to phenol vapour drives the bioelectrochemical reaction, providing a basis for a current signal under constant potential conditions. Ionic materials included Nafion and films based on tetrabutylammonium toluene-4-sulphonate (TEATS). The quasi-reversible electrode reaction of potassium hexacyanoferrate (II) within TEATS was investigated as a function of drying time. E(0) and k(0) were determined at a TEATS modified microdisc electrode under steady-state conditions. Drying time (water loss) from the TEATS film had the effect of increasing the film ionic strength. It was shown that as the film ionic strength increased, E(0) for potassium hexacyanoferrate (II) shifts toward positive potentials (because of ion pairing) and there was a corresponding increase in the heterogeneous rate constant, k(0). The latter effect was attributed to increasing ion-ion (cation-ferrocyanide ion) interactions as the film dried and the enhancing effect this had on the prevention of surface poisoning reactions at the electrode. These factors are discussed in relation to sensor design.

  • 243.
    SAINI, S
    et al.
    ; .
    TURNER, APF
    Cranfield University, UK.
    BIOSENSORS IN ORGANIC PHASES1991Inngår i: Biochemical Society Transactions, ISSN 0300-5127, E-ISSN 1470-8752, Vol. 19, nr 1, s. 28-31Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 244.
    SAINI, S
    et al.
    ; .
    TURNER, APF
    Cranfield University, UK.
    MULTIPHASE BIOELECTROCHEMICAL SENSORS1995Inngår i: TrAC. Trends in analytical chemistry, ISSN 0165-9936, E-ISSN 1879-3142, Vol. 14, nr 7, s. 304-310Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Interest in operating bioelectrochemical sensors in unconventional environments such as non-polar water-immiscible organic solvents has led to new concepts in biosensor design. This brief review considers the evolution of an approach to electrochemical measurement using thin ionically conducting films at the surface of closely spaced micro-electrodes. The ability to support ail the elements normally associated with the bioelectrochemistry of catalytic proteins at a semi-rigid ionic matrix leads to a robust sensor configuration capable of operating in non-polar solvents such as hexane or directly in gases. Such multi-phase sensors are expected to be of particular utility in environmental monitoring where measurements need to be made in water and air samples.

  • 245.
    Sandstrom, KJM
    et al.
    Natl Institute Working Life, Programme Chemistry Exposure Assessment, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90185 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Bedford MK45 4DT, England; University Tromso, Fac Science, Department Chemistry, N-9037 Tromso, Norway; .
    Carlson, R
    Natl Institute Working Life, Programme Chemistry Exposure Assessment, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90185 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Bedford MK45 4DT, England; University Tromso, Fac Science, Department Chemistry, N-9037 Tromso, Norway; .
    Sunesson, AL
    Natl Institute Working Life, Programme Chemistry Exposure Assessment, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90185 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Bedford MK45 4DT, England; University Tromso, Fac Science, Department Chemistry, N-9037 Tromso, Norway; .
    Levin, JO
    Natl Institute Working Life, Programme Chemistry Exposure Assessment, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90185 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Bedford MK45 4DT, England; University Tromso, Fac Science, Department Chemistry, N-9037 Tromso, Norway; .
    Turner, APF
    Cranfield University, UK.
    Multivariate evaluation of factors influencing the performance of a formic acid biosensor for use in air monitoring2001Inngår i: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 126, nr 11, s. 2008-2014Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A formic acid biosensor for air monitoring has been evaluated using chemometric methods. Using experimental design eleven factors that could influence the performance of the biosensor were examined. The response matrices consisted of six parameters (steady state currents at three different formic acid concentrations and response rates during changes in formic acid concentrations) describing the performance of the biosensor. The data were evaluated using a combination of principal component analysis (PCA) and multiple linear regression (MLR). To confirm the conclusions from the PCA-MLR partial least squares (PLS) was also used. The most important factor for the biosensor performance was found to be the enzyme concentration. Using the information from the chemometric analyses the optimum operation conditions for the biosensor were determined. The steady state currents were increased by 18-30% and the initial two response rates increased by 47-89% compared with a biosensor that had not been optimised.

  • 246.
    Sandstrom, KJM
    et al.
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Newman, J
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Sunesson, AL
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Levin, JO
    Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Amperometric biosensor for formic acid in air2000Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, nr 03-jan, s. 182-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The possibility of developing a simple, inexpensive and specific personal passive "real-time" air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD(+)) as a co-factor and Meldolas blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldolas blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4-15 min and the limit of detection was calculated to be below 1 mg/m(3). However, the response decreased by 50% after storage at -15 degreesC for 1 day. (C) 2000 Elsevier Science B.V. All rights reserved.

  • 247.
    Sandstrom, KJM
    et al.
    Natl Institute Working Life, SE-90713 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Silsoe MK45 4DT, Beds, England; .
    Sunesson, AL
    Natl Institute Working Life, SE-90713 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Silsoe MK45 4DT, Beds, England; .
    Levin, JO
    Natl Institute Working Life, SE-90713 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Silsoe MK45 4DT, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    A gas-phase biosensor for environmental monitoring of formic acid: laboratory and field validation2003Inngår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 5, nr 3, s. 477-482Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to encourage more exposure measurements to be performed, a formic acid gas-phase biosensor has been developed for this purpose. In the present paper, an enzyme based biosensor has been validated with respect to analyte selectivity and on-site use. To ensure that the sampler developed measures the compound of interest the biosensor was exposed to three near structural homologues to formic acid, i.e. acetic acid, methanol and formaldehyde. These vapours were generated with and without formic acid and the only compound that was found to have an effect on the performance of the biosensor, albeit a small one, was acetic acid. The field test was performed in a factory using formic acid-containing glue for glulam products. In parallel to the measurements with the biosensor a well defined reference method was used for sampling and analysing formic acid. It was found that the biosensor worked satisfactorily in this environment when used in a stationary position. It was also shown that the biosensor could determine formic acid vapour concentrations down to 0.03 mg m(-3).

  • 248.
    Sandstrom, KJM
    et al.
    Umea University, Department Publ Hlth and Clin Med, S-90581 Umea, Sweden; Natl Institute Working Life, Department Chemistry, S-90713 Umea, Sweden; Cranfield University, Cranfield Biotechnol Centre, Cranfield MK43 0AL, Beds, England; .
    Turner, APF
    Cranfield University, UK.
    Biosensors in air monitoring1999Inngår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 1, nr 4, s. 293-298Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    n/a

  • 249.
    Sandström, K. J. Mattias
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkesmedicin. Cranfield Biotechnology Centre, Cranfield University, UK; Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Newman, Jeffrey
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Sunesson, Anna-Lena
    Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Levin, Jan-Olof
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkesmedicin. Department of Chemistry, National Institute for Working Life, Umeå, Sweden.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, UK.
    Amperometric biosensor for formic acid in air2000Inngår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 70, nr 1–3, s. 182-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The possibility of developing a simple, inexpensive and specific personal passive “real-time” air sampler incorporating a biosensor for formic acid was investigated. The sensor is based on the enzymatic reaction between formic acid and formate dehydrogenase (FDH) with nicotinamide adenine dinucleotide (NAD+) as a co-factor and Meldola's blue as mediator. An effective way to immobilise the enzyme, co-factor and Meldola's blue on screen-printed, disposable, electrodes was found to be in a mixture of glycerol and phosphate buffer covered with a gas-permeable membrane. Steady-state current was reached after 4–15 min and the limit of detection was calculated to be below 1 mg/m3. However, the response decreased by 50% after storage at −15°C for 1 day.

  • 250.
    Sandström, K. J. Mattias
    et al.
    National Institute for Working Life, Umeå, Sweden.
    Sunesson, Anna-Lena
    National Institute for Working Life, Umeå, Sweden.
    Levin, Jan-Olof
    National Institute for Working Life, Umeå, Sweden.
    Turner, Anthony P. F.
    Cranfield Biotechnology Centre, Cranfield University, UK.
    A gas-phase biosensor for environmental monitoring of formic acid: laboratory and field validation2003Inngår i: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 5, nr 3, s. 477-482Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to encourage more exposure measurements to be performed, a formic acid gas-phase biosensor has been developed for this purpose. In the present paper, an enzyme based biosensor has been validated with respect to analyte selectivity and on-site use. To ensure that the sampler developed measures the compound of interest the biosensor was exposed to three near structural homologues to formic acid, i.e. acetic acid, methanol and formaldehyde. These vapours were generated with and without formic acid and the only compound that was found to have an effect on the performance of the biosensor, albeit a small one, was acetic acid. The field test was performed in a factory using formic acid-containing glue for glulam products. In parallel to the measurements with the biosensor a well defined reference method was used for sampling and analysing formic acid. It was found that the biosensor worked satisfactorily in this environment when used in a stationary position. It was also shown that the biosensor could determine formic acid vapour concentrations down to 0.03 mg m−3.

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