HATP ligand-engineered Co-MOF-74 synthesized by dielectric barrier discharge microplasma and its application in electrochemical sensing of p-benzoquinone in water samples.

p-Benzoquinone (PBQ), as a key toxic derivative of benzene, is widely present in industrial wastewater and the production and manufacturing of daily chemicals. Long-term exposure poses a serious health threat, making the development of rapid and sensitive on-site detection technologies highly significant. Electrochemical methods, due to their simple operation, high sensitivity, and ease of miniaturization, are an ideal approach for detecting PBQ. Co-MOF-74 is extensively used in the electrochemical field because of its structural stability, tunable metal nodes, and large surface area, but its low conductivity limits further applications. In this study, Co-MOF-74 was rapidly synthesized using dielectric barrier discharge (DBD) microplasma technology, and then the large π-conjugated organic ligand HATP was introduced for ligand engineering to successfully prepare Co-MOF-74-HATP. This synthesis strategy is not only efficient, but also the introduction of HATP effectively regulates the material's electronic structure, significantly enhancing its conductivity and electrocatalytic activity. The electrochemical sensor employs chronoamperometric detection at -0.15 V (vs. Ag/AgCl) and exhibits excellent performance for PBQ, featuring two wide linear ranges (17-1602 µM and 1602-5602 µM) with corresponding sensitivities of 1440 µA·mM-1·cm-2 and 497.8 µA·mM-1·cm-2, a low limit of detection (LOD) of 3.43 µM (S/N = 3), and good reproducibility (RSD < 3.0%). It was successfully applied to the detection of PBQ in actual water samples with recoveries ranging from 90.5% to 102.32%. This work expands the synthesis of ligand-functionalized MOFs through DBD microplasma technology and applies them to the electrochemical detection of PBQ in water samples.