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

In this work, Ag/bismuth oxyiodide (BiOI)/TiO 2 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 TiO 2 TiO 2 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/TiO 2 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 abstract The construction and detection mechanisms of the sensing platform Ag/BiOI/TiO 2 nanorod array were described with a detailed example of detecting chloramphenicol.