Ultrasensitive and selective detection of ciprofloxacin in milk based on organic photoelectrochemical transistor aptasensor enhanced by high capacitance Ti3C2/TiO2.

Ciprofloxacin (CIP) in milk has a harmful effect on human health, it's important to conduct ultra-sensitive selective detection of ciprofloxacin. Herein, an ultrasensitive and selective organic photoelectrochemical transistor (OPECT) CIP aptasensor was constructed using Ti 3 C 2 /TiO 2 composites as gate photoactive materials. Compared with Ti 3 C 2 , TiO 2 , and Ti 3 C 2 /TiO 2 mixed by physical, Ti 3 C 2 /TiO 2 composites exhibits larger capacitance and the OPECT intensity is 3 times of Ti 3 C 2 , 2 times of Ti 3 C 2 /TiO 2 mixed by physical and TiO 2 , which attributed to higher capacitance of Ti 3 C 2 /TiO 2 composites provides high electrostatic charge storage capacity and leads to effective gating, induces more electronic charge in the channel and larger drain currents. Exemplified by CIP as target, the developed sensor achieves sensitive detection with linear range from 3 ng/L to 3 mg/L, detection limit is 1 ng/L. This work completed the detection in real samples, which lays a foundation for the construction of OPECT food safety analysis and detection platform. • TiO 2 /Ti 3 C 2 composites was prepared by one-pot solvent hydrothermal method. • Higher capacitance of TiO 2 /Ti 3 C 2 composites greatly improves the sensitivity of OPECT aptasensor. • A sensitive and stable OPECT aptasensor for CIP detection was fabricated. • This OPECT aptasensor presented excellent performance than traditional PEC aptasensor. [ABSTRACT FROM AUTHOR]