Ultrasensitive self-powered biosensors with visual self-checking function for pathogenic bacteria detection

We proposed an enzymatic biofuel cells (EBFCs)-based biosensing platform with visual self-checking function for the ultrasensitive detection of Vibrio parahaemolyticus (Vp) with low detection limit of 2 CFU mL −1 (S/N = 3). In detail, the as-proposed biosensor was composed of the aptamer/glucose dehydrogenase/poly-thionine/carbon nanotubes/gold nanoparticles bioanode , the mediated prussian blue (PB)/ prussian white (PW) electrode with the visual self-checking function and the bilirubin oxidase/carbon nanotubes (BOD/CNTs) biocathode. Initially, the successful electron transfer from the bioanode to the PB/PW electrode could produce a high open circuit voltage ( E OCV ), accompanying with the reduction of PB to PW. Once in the presence of the target Vp , it was recognized and captured by the aptamer at the bioanode, and the E OCV obviously decreased while the color of the mediated electrode would return back to blue. Thus, the signal E OCV difference could be checked by color change, which could to a great extent avoid possible false-positive readout. In addition, the self-checking function could be recovered when connected with BOD/CNTs electrode. Overall, this work presented a prototype of an on-site tool with visual self-checking function.