| 1. |
- Piletska, EV, et al.
(författare)
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Controlled release of the herbicide simazine from computationally designed molecularly imprinted polymers
- 2005
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Ingår i: Journal of Controlled Release. - : Elsevier Science B.V., Amsterdam.. - 0168-3659 .- 1873-4995. ; 108:1, s. 132-139
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 2. |
- Albers, WM, et al.
(författare)
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Design of novel molecular wires for realizing long-distance electron transfer
- 1997
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Ingår i: Bioelectrochemistry and bioenergetics (Print). - : ELSEVIER SCIENCE SA LAUSANNE. - 0302-4598 .- 1872-8049. ; 42:1, s. 25-33
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Tidskriftsartikel (refereegranskat)abstract
- Novel heteroarene oligomers, consisting of two pyridinium groups, linked by thiophene units of variable length, thienoviologens, are described as promising candidates for molecular wires. Two representative thienoviologens were coated by adsorption from micromolar concentrations in ethanol onto octadecylmercaptan (ODM)-coated gold electrodes and induced a gradual restoration of the electrochemistry with hexacyanoferrate as a function of molecular wire concentration. Glucose oxidase and choline oxidase showed strong adsorption to these conductive layers, but showed striking differences in adsorption to the different thienoviologen layers. The measurements support the hypothesis that the molecules are incorporated in the ODM layer in a different fashion. Also the complex formation of an engineered azurin redox protein with water-soluble pyridyl ligands is presented in relation to a possible application of the thienoviologens as conductive spacers, in which the contact with the redox protein is achieved via complex formation with a free pyridine nitrogen. (C) 1997 Elsevier Science S.A.
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| 3. |
- ALCOCK, SJ, et al.
(författare)
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Continuous analyte monitoring to aid clinical practice
- 1994
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Ingår i: IEEE Engineering in Medicine and Biology Magazine. - : IEEE; 1999. - 0739-5175 .- 1937-4186. ; 13:3, s. 319-325
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Tidskriftsartikel (refereegranskat)abstract
- Considerable progress has been made in the development of practical glucose sensors for in vivo use. In some designs, the sensor can be replaced by the patient, who "injects" a new sensor into a fresh site using a hypodermic needle. An open-loop hypoglycaemia sensor providing an alarm signal could be available soon, and it would be very useful in the management of diabetes. The sensor for this application would need to function for a minimum period of about 12 hours. Further developments in the glucose sensor area are expected to lead to a comfortable implantable sensor/pump device, which would provide closed loop control for a prolonged period. An acceptable system would be a sensor replaced every 2 to 3 days, coupled with a microprocessor-controlled pump replaced after 2 to 3 years. Further engineering input is needed to design the monitoring and control unit containing the alarm and pump systems. The world market in clinical analysis is about US $6 billion, and covers about 10% of the total expenses for health care. It is in the field of continuous microsensors that future competition for the clinical diagnostic market will take place. Funding in vivo projects is less attractive to industry than the more proven and well-established area of in vitro diagnostics. However, the benefits of in vivo monitoring to the health of the community, and the financial rewards to manufacturers are ultimately great. It is clearly of interest for industry to invest in the development and commercialisation of this high added-value technology.
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| 4. |
- ALCOCK, SJ, et al.
(författare)
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THE DESIGN AND DEVELOPMENT OF NEW CHEMICAL SENSORS FOR INVIVO MONITORING
- 1991
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Ingår i: Biosensors & bioelectronics. - : Elsevier Science B.V., Amsterdam.. - 0956-5663 .- 1873-4235. ; 6:8, s. 647-652
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Tidskriftsartikel (refereegranskat)abstract
- The latest workshop of the European Community (EC) Concerted Action on Chemical sensors for in vivo monitoring was held in Nauplion, Greece, in April this year. This fifth workshop focused on The design and development of new sensors for in vivo monitoring, and was organized into five sessions: design and development of new sensors; operational considerations; performance of analytical systems; novel sensors/tissue heterogeneity; and infra-red spectroscopy.
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| 5. |
- ASTON, WJ, et al.
(författare)
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BIOSENSORS AND BIOFUEL CELLS
- 1984
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Ingår i: Biotechnology & genetic engineering reviews. - : Intercept Ltd -- England. - 0264-8725 .- 2046-5556. ; 1, s. 89-120
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Forskningsöversikt (refereegranskat)abstract
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| 6. |
- BIFULCO, L, et al.
(författare)
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TTF-MODIFIED BIOSENSORS FOR HYDROGEN-PEROXIDE
- 1994
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Ingår i: Analytical Letters. - : Taylor andamp;amp; Francis. - 0003-2719 .- 1532-236X. ; 27:8, s. 1443-1452
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Tidskriftsartikel (refereegranskat)abstract
- Amperometric biosensors for hydrogen peroxide were produced, based on TTF-modified graphite disc electrodes, incorporating immobilised peroxidase. At the optimum operating potential (-200 mV vs. calomel electrode), a Linear response to hydrogen peroxide was obtained in the range 0-2 mM (Km value = 1.98 mM). Low sensitivity to pH fluctuations and good stability at room temperature were exhibited.
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| 7. |
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| 8. |
- Bossi, A, et al.
(författare)
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An assay for ascorbic acid based on polyaniline-coated microplates
- 2000
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Ingår i: Analytical Chemistry. - : ACS American Chemical Society. - 0003-2700 .- 1520-6882. ; 72:18, s. 4296-4300
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Tidskriftsartikel (refereegranskat)abstract
- A technique for modification of the microtiter reader plates well with a polyaniline (PANI) film sensitive for ascorbic acid is presented. The principle of the analyte detection is based on monitoring the changes in optical absorption of the PANI film resulting from the reduction process initiated by ascorbic acid. The detection limit for ascorbic acid is 1 mg/L. Testing with real samples (soft drinks, fruit juices) gave good correlation of the method with iodimetric titration. High sensitivity, stability, and good reproducibility of the measurements make the proposed system an attractive alternative to traditional assays, used in medicine, ecology and biotechnology.
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| 9. |
- Bossi, A, et al.
(författare)
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Capillary electrophoresis coupled to biosensor detection
- 2000
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Ingår i: Journal of Chromatography A. - : Elsevier Science B.V., Amsterdam.. - 0021-9673 .- 1873-3778. ; 892:02-jan, s. 143-153
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Tidskriftsartikel (refereegranskat)abstract
- The present review highlights some modern aspects of biosensor revelation, a detection method which has already found a large number of applications in healthcare, food industry and environmental analysis. First, the concept of bio-recognition, which is at the heart of biosensor technology, is discussed, with emphasis on host-guest-like recognition mechanisms. This detection device has been successfully coupled, in its first applications, to chromatographic columns, which allow a high resolution of complex mixtures of analytes prior to interaction with the biosensing unit. The properties of the transducing elements, which should generate a signal (e.g., electrochemical, thermal, acoustic, optical) of proper intensity and of relative fast rise, are additionally evaluated and discussed. The review then focuses on potential applications of biosensing units in capillary electrophoresis (CE) devices. CE appears to be an excellent separation methodology to be coupled to biosensor detection, since it is based on miniaturized electrophoretic chambers, fast analysis times, complete automation in sample handling and data treatment and requires extremely small sample volumes. Although only a few applications of CE-based biosensors have been described up to the present, it is anticipated that this hyphenated technique could have a considerable expansion in the coming years, (C) 2000 Elsevier Science B.V. All rights reserved.
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| 10. |
- Bossi, A, et al.
(författare)
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Repartition effect of aromatic polyaniline coatings on the separation of bioactive peptides in capillary electrophoresis
- 2002
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Ingår i: Electrophoresis. - : John Wiley andamp;amp; Sons, Ltd. - 0173-0835 .- 1522-2683. ; 23:2, s. 203-208
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Tidskriftsartikel (refereegranskat)abstract
- The capillary walls of fused-silica capillary electrophoresis (CE) columns were modified with a thin film of polyaniline (PANI), providing open-tubular columns with a stable coating containing aromatic groups and amine functionalities. Fast and efficient separations were observed for small bioactive peptides under acidic conditions on PANI-coated columns. The mechanism of separation is based on hydrophobic interactions between the analytes and the polymeric matrix. Good reproducibility was observed from run-to-run. Due to the simple derivatization procedure, method flexibility, the uniformity of the coating and its stability, conjugated polymers could find practical application in capillary zone electrophoresis (CZE) separations.
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