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 Ti3C2/TiO2 composites as gate photoactive materials. Compared with Ti3C2, TiO2, and Ti3C2/TiO2 mixed by physical, Ti3C2/TiO2 composites exhibits larger capacitance and the OPECT intensity is 3 times of Ti3C2, 2 times of Ti3C2/TiO2 mixed by physical and TiO2, which attributed to higher capacitance of Ti3C2/TiO2 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.