The Fabrication Of MOF-based Electrochemical Sensor And Its Performance Investigation

Metal organic framework（MOF）material are porous crystals formed by coordination between organic ligands and inorganic metal ions,which are increasingly used in the field of sensors because of their advantages such as large specific surface area,tunable pore size and ordered structure.However,most of the MOF materials suffer from poor electrical conductivity and easy collapse of the structure,which can be improved by compounding with other materials.Usually,substances with good conductivity,high stability and selectivity are selected to be compounded with MOF,and the compounded materials can improve the electrochemical properties of the materials and enhance the detectability of the targets through synergistic effects.This paper develops the following studies:（1）ZIF-8 and peanut shell charcoal composites（ZIF-8@PSC）were prepared and used for the detection of Pb²⁺and Cd²⁺in domestic sewage.Characterization showed that the ZIF-8 material was successfully grown on both sides of the PSC and the introduction of PSC did not damage the structure of ZIF-8.Electrochemical studies showed that ZIF-8@PSC exhibited wide linear range,low detection limit,good reproducibility,stability and anti-interference for Pb²⁺and Cd²⁺.（2）An electrochemical sensor based on a novel conductive metal organic framework（Ni₃（HITP）₂）with silver nanomaterials of different morphologies was investigated for the detection of catechol（CA）.It was shown that three silver nanomaterials with different morphologies were successfully loaded on the surface of Ni₃（HITP）₂.By exploring the conditions such as p H and enrichment time,it was investigated that all three composites have a wide linear range,low detection limits,outstanding repeatability,reproducibility and selectivity under the optimal experimental conditions,while being suitable for the detection of real samples.（3）A composite material combining conductive MOF（CMOF）and molecularly imprinted polymer（MIP）were constructed using chitosan and conductive carbon black（CS-CB）as reaction substrates for the highly sensitive detection of dopamine（DA）.The CS-CB/CMOF/MIP sensor provided good detection of DA in the range of 0.06 to 200μM L^-1,with detection limits as low as 0.109μM L^-1.The superior performance in the detection of DA compared to conventional electrochemical sensors is attributed to the good electrical conductivity and specific recognition sites of the sensor.