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 Bi2WO6 (BWO-1) and Ag2S 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, AgNO3 concentration of 0.14 mol/L, ascorbic acid (AA) concentration of 0.13 mol/L, pH value of 7.4, aptamer concentration of 2 ?mol/L, and incubation time of 50 min, had an optimal photocurrent responsiveness. The developed method showed a wide linear range from 3.2 ? 102 CFU/mL to 3.2 ? 108 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.

Automated summary

In this study, a photoelectrochemical (PEC) aptamer sensor was constructed using a layer-by-layer self-assembly method, with rare-earth doped Bi2WO6 and Ag2S as photoactive materials to enhance photocurrent responsiveness under visible light. The optimized experimental conditions showed high detection specificity and stability for Vibrio parahaemolyticus, indicating the potential of this method for rapid detection of other food-borne pathogenic bacteria.