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- Karimian, N, et al.
(författare)
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On/off-switchable electrochemical sensor for folicacid based on molecularly imprinted technology.
- 2013
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 36, s. 92-95
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Tidskriftsartikel (refereegranskat)abstract
- The combination of smart polymers with molecular imprinting offers a powerful tool to design more effective sensors and medical devices. In this study, a temperature sensitive amine-terminated poly(N-isopropylacrylamide) block with (N,N'-methylenebisacrylamide) cross-linker along with o-phenylenediamine was electropolymerised on a gold electrode in the presence of folic acid (FA) as template to produce an on/off-switchable molecularly imprinted polymer (MIP) affinity sensor for folic acid. Differential pulse voltammetry and cyclic voltammetry were used to characterise the FA-imprinted layer. Incubation of the MIP-modified electrode with FA resulted in a suppression of the ferro/ferricyanide redox process. The highest sensitivity of this temperature gated on/off-switchable folic acid sensor was achieved at 22 °C. Such switchable affinity materials offer considerable potential for the design of highly selective and controllable biosensors and immunoassays.
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| 4. |
- Sheikhzadeh, E., et al.
(författare)
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Label-free impedimetric biosensor for Salmonella Typhimurium detection based on poly [pyrrole-co-3-carboxyl-pyrrole] copolymer supported aptamer
- 2016
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Ingår i: Biosensors & bioelectronics. - : ELSEVIER ADVANCED TECHNOLOGY. - 0956-5663 .- 1873-4235. ; 80, s. 194-200
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Tidskriftsartikel (refereegranskat)abstract
- The Gram-negative bacterium, Salmonella Typhimurium (S. Typhimurium) is a food borne pathogen responsible for numerous hospitalisations and deaths all over the world. Conventional detection methods for pathogens are time consuming and labour-intensive. Hence, there is considerable interest in faster and simpler detection methods. Polypyrrole-based polymers, due to their intrinsic chemical and electrical properties, have been demonstrated to be valuable candidates for the fabrication of chemo/biosensors and functional surfaces. Similarly aptamers have been shown to be good alternatives to antibodies in the development of affinity biosensors. In this study, we report on the combination of Poly [pyrrole-co-3-carboxyl-pyrrole] copolymer and aptamer for the development of a label-less electrochemical biosensor suitable for the detection of S. Typhimurium. Impedimetric measurements were facilitated by the effect of the aptamer/target interaction on the intrinsic conjugation of the poly [pyrrole-co-3-carboxyl-pyrrole] copolymer and subsequently on its electrical properties. The aptasensor detected S. Typhimurium in the concentration range 10(2)-10(8) CFU mL(-1) with high selectivity over other model pathogens and with a limit of quantification (LOQ) of 100 CFU mL(-1) and a limit of detection (LOD) of 3 CFU mL(-1). The suitability of the aptasensor for real sample detection was demonstrated via recovery studies performed in spiked apple juice samples. We envisage this to be a viable approach for the inexpensive and rapid detection of pathogens in food, and possibly in other environmental samples. (C) 2016 Elsevier B.V. All rights reserved.
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| 5. |
- Sheikhzadeh, Elham, et al.
(författare)
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Label free impedimetric Salmonella aptasensor based on pyrrole (pyrrole -3-carboxyl acid ) copolymer.
- 2015
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Ingår i: <em>Sweden-Japan Seminar on Nanomaterials and Nanotechnology – SJS-Nano</em>, Linköping, Sweden, 10-11 March 2015. - : Japan Society for the Promotion of Science (JSPS), Stockholm.. ; , s. 32-33
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Konferensbidrag (refereegranskat)abstract
- Salmonella is a Gram-negative foodborne pathogen that can cause gastrointestinal infection that is the cause of numerous hospitalisations and deaths all over the world [1]. Conventional approaches for Salmonella detection, based on culture methods, are time-consuming and labour-intensive; this creates considerable need for the development of novel, fast and reliable approaches.Conductive polymers are poly-conjugated systems that present, at the same time, the properties of conductive materials and conventional polymers. Among them, polypyrrole and its derivatives are attracting a lot of attention in several fields including actuators and biosensors [2]. Aptamers are single strand of DNA or RNA that can bind to specific target with high affinity showing in this way great potentiality as alternative to antibodies in affinity based biosensors [3]. In the study presented herein the preparation, via electrodeposition, of a copolymer based on pyrrole and pyrrol 3-carboxylic acid and its application in the development of an aptamer based biosensor is presented. Immobilisation of aptamers, via EDC /NHS chemistry onto the synthetised polymer has been demonstrated via electrochemical techniques. The detection of different concentration of Salmonella was performed by incubation of the prepared electrode with different concentrations of bacteria, followed by impedance measurement in LiClO4 solution. A Nyquist plot of impedance spectra showed increase in the radii of the semicircle, corresponding to an increased charge transfer resistance, and associated to the interaction between the immobilised aptames and the bacteria in the sample. This initial result suggests that it should be possible to create a label-free sensor based on this method. [1] J. Yuan, Z. Tao, Y.Yu, X. Ma, Y. Xia, L. Wang, Z. Wang,Food Control 37 (2014) 188 – 192[2] R. Balint, N. J. Cassidy, S. H. Cartmell, Acta Biomaterialia 10 (2014) 2341–2353[3] S. Tombelli, M. Minunni, M. Mascini, Biosensors and Bioelectronics 20 (2005) 2424–2434
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