MIL-88B(Fe) MOF Modified Screen-Printed Electrodes for Non-Enzymatic Electrochemical Sensing of Malathion.

An enzyme-free electrochemical approach for ultra-trace quantification of the organophosphate insecticide malathion is proposed in this study. It is premised on screen-printed carbon electrodes modified by the MIL-88B(Fe) metal-organic framework (MOF). A one-pot solvothermal method was used to synthesize MIL-88B(Fe). The surface modification of electrodes allowed for increased electroactive surface area and accelerated electron transport on the electrode. Inhibition in the redox signal of MIL-88B(Fe) was observed due to the affinity between metal centers of the MOF and the functional groups of malathion, leading to an accurate determination of malathion. The proposed sensor effectively quantified malathion in the wide concentration range of 1x10 -12 M to 1x10 -6 M. The limit of detection for malathion was 0.79 pM. The proposed sensor also possessed excellent stability, repeatability, and anti-interference characteristics. Furthermore, the proposed sensor demonstrated satisfactory malathion recovery in spiked vegetable samples.Highlights MIL-88B(Fe) MOF was characterized by XRD, XPS, FTIR, SEM, and Raman spectroscopy.MIL-88(Fe) modified screen-printed carbon electrodes for electrochemical assay.Applied for direct malathion quantification in spiked vegetable samples.The sensor demonstrated a limit of detection of 0.79 pM towards malathion.