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

[Display omitted] •An enzymatic biofuel cells-based biosensing platform is proposed.•The biosensing platform possesses visual self-checking function.•The limit of detection for Vibrio parahaemolyticus was 2 CFU mL−1 (S/N = 3). 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 (EOCV), 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 EOCV obviously decreased while the color of the mediated electrode would return back to blue. Thus, the signal EOCV 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.