Bi 2 WO 6 /Ti 3 C 2 MXene Quantum Dots Heterostructure-Based Label-Free Photoelectrochemical Aptamer Sensor for Ultrasensitive Kanamycin Monitoring

Abstract

As Kanamycin (KAN) is an amino-glycoside antibiotic and has seriously negative effects towards human health, it is urgent to develop an effective way for KAN monitoring. Herein, Bi 2 WO 6 /Ti 3 C 2 MXene quantum dots (Bi 2 WO 6 /Ti 3 C 2 QDs) heterostructure was synthesized by electrostatically driven assembly and hydrothermal method. On the basis of a Bi 2 WO 6 /Ti 3 C 2 QDs heterostructure, a novel aptamer-based anodic photoelectrochemical (PEC) sensing platform was constructed. Through the formation of Au–S bond, the mercapto-group modified aptamers were immobilized as a recognition unit for KAN. Under visible light irradiation, this PEC platform exhibits excellent signal-on photocurrent in the presence of KAN. A log-linear response is observed over a KAN concentration range from 0.01 nM to 50 nM, with a detection limit of 0.005 nM. Moreover, this aptamer-sensor can accurately detect KAN in animal product samples, with recoveries ranging from 94.2% to 101.3%. Overall, this work demonstrates the considerable potential of component reconstitution in PEC biosensors for real sample analysis, providing a new perspective on PEC sensor development.