| 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. |
- Jiang, TS, et al.
(författare)
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Detection of TP53 mutation using a portable surface plasmon resonance DNA-based biosensor
- 2005
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Ingår i: Biosensors & bioelectronics. - : Elsevier Science B.V., Amsterdam.. - 0956-5663 .- 1873-4235. ; 20:10, s. 1939-1945
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Tidskriftsartikel (refereegranskat)abstract
- A DNA-based surface plasmon resonance (SPR) biosensor has been developed for the detection of TP53 mutation using the inexpensive and commercially available instrument, SPREETA (TM) SPR-EVM-BT, from Texas Instruments. A direct immobilisation procedure, based on the coupling of thiol-derivatised oligonucleotide probes (Probe-C6-SH) to bare gold sensor surfaces, was optimized using synthetic oligonucleotides. Hybridisation reactions between the immobilised probe and a short sequence (26 mer) complementary, non-complementary and one-point mutation DNA were then investigated. The main analytical parameters of the sensor system were studied in detail including selectivity, sensitivity, reproducibility and analysis time. Finally, the sensor system was successfully applied to polymerase chain reaction (PCR)-amplified real samples, DNA extracted from both normal, wild-type, (Jurkat) and mutated (Molt 4), carrying the mutation at codon 248 of the TP53 cell lines. The results obtained demonstrate that the DNA-based SPR biosensor was able to distinguish sequences present in the various samples that differ only by one base; and hence, it appears to be a strong candidate technique for the detection of gene mutation. (c) 2004 Elsevier B.V. All rights reserved.
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| 3. |
- Meglinski, IV, et al.
(författare)
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Laser ice scaffolds modeling for tissue engineering
- 2005
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Ingår i: LASER PHYSICS LETTERS. - : John Wiley andamp;amp; Sons, Ltd. - 1612-2011 .- 1612-202X. ; 2:9, s. 465-467
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Tidskriftsartikel (refereegranskat)abstract
- Tissue engineering is one of the most exciting and rapidly growing areas in biomedical engineering that offers vast potential for changing traditional approaches to meeting many pharmaceutics and critical health care needs. Currently the bottle-neck area in this multidisciplmiary field appears to be materials and fabrication technology for the design of artificial extracellular matrices/scaffolds that support culturing and growth of new tissue. We have shown that stable relief structures can be created and maintained in the bulk of ice by continuous s canning with computer-guided IR CO2 laser. The optimal laser beam intensity and fluence rate distribution within the ice sample, as well as the rate of scanning were estimated based on the Monte Carlo model utilized physical/optical properties of ice. The results of numerical simulation are agreed well with the observed experimental results of thermo-coupling measurements and obtained microscopic images.
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| 4. |
- Newman, JD, et al.
(författare)
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Home blood glucose biosensors: a commercial perspective
- 2005
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Ingår i: Biosensors & bioelectronics. - : Elsevier Science B.V., Amsterdam.. - 0956-5663 .- 1873-4235. ; 20:12, s. 2435-2453
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Forskningsöversikt (refereegranskat)abstract
- Twenty years on from a review in the first issue of this journal, this contribution revisits glucose sensing for diabetes with an emphasis on commercial developments in the home blood glucose testing market. Following a brief introduction to the needs of people with diabetes, the review considers defining technologies that have enabled the introduction of commercial products and then reviews the products themselves. Drawing heavily on the performance of actual instruments and publicly available information from the companies themselves, this work is designed to complement more conventional reviews based on papers published in scholarly journals. It focuses on the commercial reality today and the products that we are likely to see in the near future. (c) 2004 Elsevier B. V. All rights reserved.
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| 5. |
- Piletska, EV, et al.
(författare)
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Adaptation of the molecular imprinted polymers towards polar environment
- 2005
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Ingår i: Analytica Chimica Acta. - : Elsevier Science B.V., Amsterdam.. - 0003-2670 .- 1873-4324. ; 542:1, s. 47-51
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
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| 7. |
- Piletsky, SA, et al.
(författare)
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Polymer cookery: Influence of polymerization time and different initiation conditions on performance of molecularly imprinted polymers
- 2005
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Ingår i: Macromolecules. - : ACS American Chemical Society. - 0024-9297 .- 1520-5835. ; 38:4, s. 1410-1414
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Rasinger, JD, et al.
(författare)
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Evaluation of an FIA operated amperometric bacterial biosensor, based on pseudomonas putida F1 for the detection of benzene, toluene, ethylbenzene, and xylenes (BTEX)
- 2005
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Ingår i: Analytical Letters. - : Taylor andamp;amp; Francis. - 0003-2719 .- 1532-236X. ; 38:10, s. 1531-1547
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 9. |
- Sarkar, P, et al.
(författare)
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Screen-printed biosensor for allergens
- 2005
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley andamp;amp; Sons, Ltd. - 0268-2575 .- 1097-4660. ; 80:12, s. 1389-1394
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Tidskriftsartikel (refereegranskat)abstract
- Allergen levels in indoor environments, leading to many diseases, eg asthma, rhinitis and conjunctivitis, affect a large and increasing fraction of the population. A quite effective and inexpensive method of a rough but very rapid overall assessment of total allergen level in the environment has been developed. The method involved estimation of protein in allergen extracts by screen-printed electrodes using two different techniques. The biosensor comprised a rhodinised carbon working electrode, a silver/silver chloride reference electrode and a carbon counter electrode. In the first method the enzyme protease reacted with allergen protein to release amino acid, which produced hydrogen peroxide in the presence of amino acid oxidase. This was detected amperometrically. The second method used potassium bromide as electrolyte and the electrode was subjected to dual potential. Bromine, released due to electrolysis at higher potential, was consumed by the allergen protein at lower potential. In the first method, a unique technique was used to microencapsulate the enzyme protease and immobilise it on the surface of the electrode by in-situ polymerisation to avoid contact with the amino acid oxidase. A total of seven allergens were tested and the results gave a good correlation with the standard protein measurement method. Environmental specimens from indoors, schools and workplaces can be evaluated for the aeroallergens produced by dust mites, animal hairs, cockroach debris, pollens, etc as a means of determining the exposure risk. (c) 2005 Society of Chemical Industry.
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