Synergistic effect of silver plasmon resonance and p-n heterojunction enhanced photoelectrochemical aptasensing platform for detecting Chloramphenicol

In this work, Ag/bismuth oxyiodide (BiOI)/TiO2 nanorod array (NRA) is used as the visible light active material, and chloramphenicol (CAP) aptamer is used as the original biological identification. A photoelectrochemical (PEC) aptasensing system for the specific detection of CAP is designed. The p-n heterojunction constructed by p-type BiOI nanosheets and n-type TiO2 TiO2 NRA facilitates electron transfer and improves the separation efficiency of the photogenerated electron-hole pairs. Furthermore, the Ag nanoparticles with surface plasmon resonance (SPR) enhance the light absorption range and provide a Z-scheme transfer mechanism for electrons. The CAP aptamer was fixed to the Ag/BiOI/TiO2 NRA through the C =N structure as the recognition unit of CAP. The detection platform shows good detection performance in the linear response range of 1 nM to 250 nM and has high selectivity, with a detection limit of 0.27 nM (S/N = 3). The constructed sensor can be applied to CAP detection in food.

Automated summary

In this study, a photoelectrochemical aptasensing system based on Ag/bismuth oxyiodide/TiO2 nanorod array was developed for specific detection of chloramphenicol. The system showed good detection performance within a linear response range, high selectivity, and a low detection limit.