Persulfate mediated single-channel bimodal self-checking light-assisted self-powered aptasensor for highly accurate assay

Developing multiple signals are needed for self-powered sensors to improve the detection accuracy. Herein we designed a novel dual-power-peak photofuel cell (PFC) based self-powered sensors with persulfate as an initiator. Persulfate expands photocatalytic redox reactions of PFC system, which enhanced separation of electrons and holes and more importantly, reduced the ohmic loss (ηohmic) efficiency and formed a second power peak for the first time. Such a self-powered sensor could self-check by using two separate power peaks in the same signal-readout window, greatly improving the accuracy compared with a single-peak-signal one. Moreover, the introduction of V2C MXene further accelerated the electron transfer and improved the photoelectric conversion efficiency. The aptamer was immobilized on the photoanode for the specific detection of the model analyte chloramphenicol and the reliable quantification was achieved via dual-power-peak density values from the single photoanode interface. Under optimum conditions, the linear range of this self-powered aptasensor was 0.5 pM to 3 nM, with a detection limit of 0.17 pM. As a result, a novel self-powered aptasensor was developed successfully based on the strategy of persulfate induced dual-power-peak, showing great promise in the development of multi-signal sensors with high accuracy and specificity.