A novel photoelectrochemical aptamer sensor based on rare-earth doped Bi2WO6 and Ag2S for the rapid detection of Vibrio parahaemolyticus

In this work, layer-by-layer self-assembly method was used to construct the working electrode of the photoelectrochemical (PEC) aptamer sensor. Rare-earth doped Bi 2 WO 6 (BWO-1) and Ag 2 S are combined as highly efficient photoactive material to reduce the recombination rate of electron-hole pairs and enhance the photocurrent responsiveness under visible light. The PEC aptamer sensor, with BWO-1 concentration of 12 mg/mL, AgNO 3 concentration of 0.14 mol/L, ascorbic   acid (AA) concentration of 0.13 mol/L, pH value of 7.4, aptamer concentration of 2 μmol/L, and incubation time of 50 min, had an optimal photocurrent responsiveness. The developed method showed a wide linear range from 3.2 × 10 2 CFU/mL to 3.2 × 10 8 CFU/mL. The detection limit was 40 CFU/mL. The constructed PEC aptamer sensor exhibited good detection specificity, stability and reproducibility for Vibrio parahaemolyticus and provided a simple, low-cost and rapid detection strategy for prevention and control of foodborne diseases. This method could be promising for the rapid detection of other food-borne   pathogenic   bacteria in the food.