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 . 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 .
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 .
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.
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Japan Society for the Promotion of Science (JSPS), Stockholm. , 2015. 32-33 p.
Sweden-Japan Seminar on Nanomaterials and Nanotechnology – SJS-Nano, Linköping, Sweden, 10-11 March 2015