[Ru(bpy)]@Ce-UiO-66/Mn:BiS Heterojunction and Its Exceptional Photoelectrochemical Aptasensing Properties for Ofloxacin Detection.

A photoelectrochemical (PEC) aptasensor on basis of [Ru(bpy)]@Ce-UiO-66/Mn:BiS composites was constructed for detecting ofloxacin (OFL). First, Ce-UiO-66, prepared by a solvothermal method, had Zr-Zr and Ce-Ce intervalence cycles to increase the charge separation efficiency. Subsequently, Ce-UiO-66 was further modified by [Ru(bpy)] and Mn:BiS cosensitization to improve the photoelectric activity. [Ru(bpy)] not only broadened the range of light absorbed but also reacted with an electron donor to maintain the photoelectric conversion process. Among the [Ru(bpy)]@Ce-UiO-66/Mn:BiS heterojunction, Mn:BiS was a photosensitizer, which maximized the efficiency of the electron-hole separation and significantly improved photocurrent. Then, an aptamer was used as a biorecognition unit for OFL-specific detection. Under the best conditions, the PEC aptasensor realized the sensitive detection of OFL, with a detection range of 0.01-100 nmol/L and a detection limit of 6 pmol/L. In addition, the constructed PEC OFL sensor showed good reproducibility, stability, and specificity.