A highly sensitive MXene/AuPt/AChE-based electrochemical platform for the detection of chlorpyrifos

The MXene/AuPt nanocomposite was successfully synthesized through the reduction process, which possessed good biocompatibility and electron transfer capability. On the basis of the excellent performance of MXene/AuPt and the enzyme inhibition, an ultrasensitive and high-performance acetylcholinesterase (AChE)-based electrochemical biosensor was prepared for the detection of chlorpyrifos. The prepared biosensor combined the unique electrocatalytic property and synergistic effect of MXene nanosheets and AuPt bimetallic nanoparticles, which not only promoted the electron transfer capability, but also increased the electroactive surface area for the immobilization of AChE. The electrochemical performance was investigated by cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry. This biosensor exhibited good affinity towards AChE with a corresponding apparent Michaelis constant (Km) of 1.27 mM. Under optimal conditions, the electrochemical biosensing platform presented a good linear relationship in the range of 10−8−10−3 mg mL−1 and a low limit of detection of 1.55 pg mL−1. Furthermore, the as-prepared electrochemical biosensor exhibited high sensitivity, acceptable repeatability, and excellent stability, which implied the great potential for the detection of organophosphorus pesticides.