Conducting polymer nanowire-based chemiresistive biosensor for the detection of bacterial spores

Polypyrrole nanowires (Ppy) were assembled onto microfabricated gold interdigitated microelectrodes, to construct a chemiresistive biosensor for the detection of Bacillus globigii, used as simulant of the threatening bioterrorism agent B. anthracis. The fabricated biosensor showed good linear correlation (r(2)=0.992) for low spore concentrations ranging from 1 to 100 CFU (colony forming units)/mL, a concentration that could be used in a bioterrorism attack, with a response time of 30 min, after which the sensor was saturated. The performance of the biosensor was also assessed in the absence of anti-B. globigii antibodies and in the presence of non-target bacterial cells (Escherichia coli) showing no significant non-specific interactions. We believe that Ppy nanowires are a good platform for the detection and also quantification of large molecules and biocomponents even at low concentrations.