Two birds with one stone: Dual-functional MXene/WS2/Au NPs heterostructures for Staphylococcus aureus photoelectrochemical assay and broad-spectrum antibacterial properties

Staphylococcus aureus ( S. aureus ), a prevalent foodborne pathogen, poses a significant threat to public health. Rapid, specific, and sensitive on-site pathogen detection methods are crucial for food safety. In this study, a ternary MXene/WS 2 /Au NPs composite was synthesized via a solvothermal and in situ growth method. This composite serves dual purposes as a photoactive material for photoelectrochemical (PEC) aptasensing and as an effective antibacterial catalyst. A PEC aptasensor was developed using MXene/WS 2 /Au NPs as the substrate and a ferrocene-modified aptamer as the recognition probe, enabling quantitative detection of S. aureus . The sensor exhibits a wide linear range (1.0 × 10–1.0 × 10 7 CFU/mL) and an ultra-low detection limit (3.0 CFU/mL). Additionally, the nanocomposite demonstrates strong peroxidase-like activity, efficiently catalyzing H 2 O 2 to generate ·OH, offering broad-spectrum antibacterial properties for pathogen control in food safety monitoring.