A visible and near-infrared light dual-responsive PEC immunosensor for archaeological silk microtrace detection based on in situ growth of Ag2S on ZnO-MXene nanocomposites

Developing an effective analytical method for microtrace detection of ancient silk is highly desirable and vitally crucial for exploring the origin and spread of silk. Herein, a taxonomically specific anti-fibroin monoclonal antibody was prepared and an elaborate visible/near-infrared (vis/NIR) photoelectrochemical (PEC) immunosensor was proposed. The sensor employed Ag 2 S nanoparticles (NPs) grown in situ on ZnO nanowire array-MXene nanocomposites (ZnO-MX) via a sonochemical method as a photosensitive material. The experimental results illustrated that the ZnO-MX/Ag 2 S-based sensor presented 6.8 times larger PEC responses than a ZnO-MX-based sensor under visible light illumination, and the PEC signal of the ZnO-MX/Ag 2 S nanocomposites was 30 times as high as that of ZnO-MX under 808 nm NIR light, indicating enhanced photoelectric activity and a matched energy band structure of ZnO with MXene and Ag 2 S. This PEC immunosensor exhibited excellent potential for the ultrasensitive detection of Bombyx mori silk traces due to its wide linear range of 0.005–50 ng mL −1 and low detection limit of 1.51 pg mL −1 . Additionally, the immunosensor showed outstanding specificity, stability, and repeatability, particularly for the qualitative detection of archeological artifacts. Given its aforementioned benefits, ZnO-MX/Ag 2 S nanocomposites are potentially attractive photoactive materials for use in vis/NIR PEC immunosensors. Moreover, this demonstrated method offers a feasible method to investigate the history and distribution of ancient silk.