Triple-Template Molecularly Imprinted Electrochemical Sensor Based on Ni,Co/NC@CNTs Derived from ZIF-67 for Highly Sensitive Simultaneous Detection of Dihydroxybenzene Isomers

The structural and chemical similarities of isomers pose significant challenges for their accurate and simultaneous determination. In this study, for the first time, a novel triple-template molecularly imprinted electrochemical sensor (MIP-ECS) was constructed for the simultaneous, highly sensitive differentiation and detection of three dihydroxybenzene isomers. Benefiting from the porous structure provided by the ZIF derivative, the in situ-grown highly graphitized carbon nanotubes (CNTs) and the highly dispersed bimetallic nanoparticles provide abundant active sites for the electrocatalytic oxidation of isomer molecules and accelerate the charge-transfer rate. Under the optimal experimental conditions, the MIP/Ni,Co/NC@CNTs shows a wide linear range for the simultaneous detection of HQ, CC, and RC (0.2-303 μM for HQ, 0.2-213 μM for CC, and 5-230 μM for RC), with detection limits of 11.81 nM for HQ, 17.47 nM for CC, and 344.2 nM for RC, respectively. Meanwhile, the MIP-ECS also exhibits excellent stability and selectivity and has been successfully applied to the determination of the three isomers in real samples (landfill leachate, textile wastewater, and tap water) with a recovery range of 97.1-103.8%. This work applies ZIF-derived and carbon nanocomposites to multitemplate MIPs, providing a revolutionary method for the specific recognition and simultaneous detection of isomers in the environment.