(200) Facet regulation on Bi12O17Cl2 nanosheets driven charge separation for enhancing photoelectrochemical ciprofloxacin aptasensing

Photoelectrochemical (PEC) aptasensor with high sensitivity, quick response, facile miniaturization, and low-cost has emerged as a prospectively method for detecting ciprofloxacin (CIP). A crucial issue in constructing PEC aptasensor is how to modulate photogenerated charges behaviors of photoelectric active materials. Bi12O17Cl2 nanosheets with exposed (200) facets have been designed and prepared in this work, which exhibited the open charge channel characteristic, narrow band gap, strong visible light harvesting ability, and significantly broadened light absorption range. These characteristics are conducive to the effective generation, separation and transfer of charges for possessing strong photocurrent signal. Based on the Bi12O17Cl2 nanosheets with exposed (200) facets and CIP aptamer with specific recognition ability, a PEC aptasensor was constructed for detecting CIP. The PEC aptasensor showed a detection range of 1.00 x 10-2-1.00 ng L-1 and the detection limit of 3.33 pg L-1 (S/N = 3). The constructed PEC aptasensor also can demonstrate good sensitivity, selectivity, reproducibility, and feasibility.