Quantitative analysis of Fumonisin B1 using photoelectrochemical aptamer sensing strategy based on dual type II heterojunction K3PW12O40/CdS/CoSx.

Fumonisin B1 (FB1) is a highly toxic fungal toxin that poses a serious threat to human health. Accordingly, realizing highly sensitive detection of FB1 is essential to safeguard people's health. In this study, a photoelectrochemical (PEC) aptamer sensor was successfully constructed with K3PW12O40/CdS/CoSx as the substrate material and with AgBiS2 as the aptamer marker. Importantly, the utilization of AgBiS2 as an aptamer marker can regulate the electron transfer pathway, resulting in a clear decrease in the photocurrent value. Due to the strong affinity between FB1 and its aptamer (t-DNA), it will cause the photoanode to release t-DNA-AgBiS2, which can realize the effective recovery of photocurrent. Furthermore, the synthesized PEC aptamer sensor enables sensitive detection of FB1 and has a wider linear range of 100 fg/mL ∼1 μg/mL with a detection limit as low as 4.9 fg/mL. In short, this study provides a feasible PEC aptamer sensor strategy for sensitive detection of FB1, which paves a new way for the detection of other mycotoxins.