Keywords Photoelectrochemical; Aptamer; Nanocomposites; Sensor; Vibrio parahaemolyticus Highlights * A novel photoelectrochemical aptamer sensor was successfully constructed. * The work conditions of sensor based on rare-earth doped Bi.sub.2WO.sub.6 and Ag.sub.2S were optimized. * The aptamer sensor exhibited good detection specificity, stability and reproducibility. * This study provides a rapid detection method 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.sub.2WO.sub.6 (BWO-1) and Ag.sub.2S 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.sub.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 mumol/L, and incubation time of 50 min, had an optimal photocurrent responsiveness. The developed method showed a wide linear range from 3.2 x 10.sup.2 CFU/mL to 3.2 x 10.sup.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. Author Affiliation: (a) Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China (b) Liaoning Key Lab for Aquatic Processing Quality and Safety, Dalian Polytechnic University, Dalian 116034, China * Corresponding authors at: Department of Inorganic Nonmetallic Materials Engineering, Dalian Polytechnic University, Dalian 116034, China. Article History: Received 17 October 2020; Revised 10 February 2021; Accepted 1 March 2021 (footnote)1 Authors Yunxia and Liangliang are the co-first author, and they contribute equally. Byline: Yunxia Hou (a,1), Liangliang Zhu (a,1), Hongshun Hao beike1952@163.com (a,b,*), Zuowei Zhang (a), Chao Ding (a), Gongliang Zhang (b), Jingran Bi (b), Shuang Yan (a), Guishan Liu (a), Hongman Hou houhongman@dlpu.edu.cn (b,*)