Cobalt(II)-ion-exchanged Zn-bio-MOF-1 derived CoS/ZnS composites modified electrochemical sensor for chloroneb detection by differential pulse voltammetry.

For the first time CoS-nanoparticles attached ZnS rods (CoS/ZnS composites) have been synthesized using cobalt(II)-ion-exchanged zinc-based biological metal-organic framework-1 (Zn-bio-MOF-1) as precursors by a solvothermal method. Among them, the cobalt(II)-ion-exchanged Zn-bio-MOF-1 was obtained by exchanging the dimethylammonium cations (MeNH) of Zn-bio-MOF-1 with cobalt ions. A novel electrochemical sensor based on CoS/ZnS composites and molecularly imprinted polymers (MIPs) was proposed for rapid, sensitive, and highly selective detection of organochlorine pesticide chloroneb. The MIP film was obtained by cyclic voltammetry (CV), and differential pulse voltammetry (DPV) was used to detect chloroneb. Under the optimal conditions, the oxidation peak current density of chloroneb was linearly related to the concentration from 0.003 to 0.2 μM and 0.2 to 3.2 μM with a detection limit of 0.87 nM (S/N = 3) and a sensitivity of 52.27 μA·μM·cm. The proposed sensor exhibits a favorable selectivity, stability, and reproducibility, and was applied to detect chloroneb residues in licorice, cucumber, river water, and soil samples with satisfactory results.Graphical abstract.