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.Graphical abstractThe construction and detection mechanisms of the sensing platform Ag/BiOI/TiO2 nanorod array were described with a detailed example of detecting chloramphenicol.