Sensitive photoelectrochemical aptasensing of Salmonella enteritidis based on AgBiS2 and Ag/g-C3N4 with gold nanoparticles

In this paper, an ultrasensitive photoelectric chemical sensor based on AgBiS₂ and Ag/g-C₃N₄ was prepared for the detection of Salmonella enteritidis (SE). The AgBiS₂ and Ag/g-C₃N₄ were modified on FTO by layer modification to increase the photoelectric activity of the electrode, the gold nanoparticles continued to be modified, and the aptamer of SE was fixed by AuS bond to realize the specific detection of SE. Compared with the AgBiS₂-modified electrode, the electrode prepared by the composite material produced a significantly enhanced and stable photocurrent signal under Xe lamp irradiation. The detection limit of sensor was 2.18 CFU/mL, and ideally, the concentration of SE detection would show a good linear relationship between 6.72 × 10³ CFU/mL and 6.72 × 10⁸ CFU/mL. The constructed photoelectrochemical sensor has strong sensitivity, wide linear range, and good selectivity for potential pathogenic bacteria. Therefore, this study provides a very promising photoelectric chemical platform for the detection of SE.