A novel electrochemical sensor based on molecularly imprinted polymer-modified C-ZIF67@Ni for highly sensitive and selective determination of carbendazim.

In this work, we propose a two-step coating method, combining C-ZIF67@Ni with molecular imprinting polymer (MIP), to develop a high-sensitivity and high-selectivity Carbendazim (CBD) electrochemical sensor. ZIF67@Ni was prepared by a simple chemical bath method, and C-ZIF67@Ni was obtained by high-temperature carbonization of ZIF67@Ni. Then, MIP layer was prepared by electrochemical in-situ polymerization, with O-aminophenol as functional monomers, CBD acting as template on the surface of the C-ZIF67@Ni-modified glassy carbon electrode (GCE). During the preparation process, the types of functional monomers, the polymerization solution pH, the ratio of functional monomers to template molecules, and the incubation time are optimized. The morphological characteristics, composition information and electrochemical properties of MIP/C-ZIF67@Ni/GCE were investigated in detail under optimal conditions. Physical characterization and electrochemical tests revealed that ZIF67@Ni significantly improves the electron transmission capacity and surface area of the sensor after high-temperature carbonization. C-ZIF67@ Ni has a good synergistic effect on MIP, allowing rapid and specific identification of the test substance. MIP/C-ZIF67@Ni/GCE showed a good linear relationship with CBD in the concentration range from 4 × 10 M to 1 × 10 M, the lowest detection limit was 1.35 × 10 M (S/N = 3) R = 0.9983 and RSD = 2.34. Additionally, the sensor showed good repeatability, stability, and selectivity, and can be used for the detection of carbendazim in soil and water with a recovery of 98% above.