Dual-photoelectrode photocatalytic fuel cell-assisted self-powered biosensor: An ingenious and sensitive strategy for p53 gene detection

Self-powered sensors have the advantages of no external power supply, energy conversion in the environment and easy miniaturization, making it an attractive choice for building implantable, wearable and portable devices. However, it is difficult to sensitively detect low abundance targets owing to their poor output performance and interference from complicated settings. Herein, a new photocatalytic fuel cell-based self-powered electrochemical biosensor (PFC-SPEB) was proposed for the detection of p53 gene by combining high photocatalytic performance In2S3 and CuInS2 with magnetic nanobeads-assisted signal amplification strategy. In2S3 photoanode and CuInS2 photocathode were combined to form a dual photoelectrode system with an open-circuit potential up to 705.9 mV, which improved the photoelectric conversion efficiency by 1.4-6.9 folds compared with that of single photoelectrode system. Furthermore, the enzyme-assisted signal amplification strategy made a small number of p53 genes trigger the creation of abundant double-stranded DNA (dsDNA). Finally, manganese porphyrin was inserted into dsDNA to stimulate precipitation reactions on surfaces of the photoanode, leading to a sharp drop of signal. The constructed PFC-SPEB exhibited a wide linear detection range from 10 fM to 10 nM with a low detection limit of 1.40 fM, providing new creative inspiration for constructing SPEB for bioanalysis and clinical diagnostics.