Designing and Fabrication of MOF Based Electrochemical Sensor for Potential Application in Environmental Remediation2025

Abstract

Contamination of fresh water bodies by heavy metal ions (HMIs) has been a concern across the world. Due to its bioaccumulation and non-degradability, lead (Pb) and mercury (Hg) are some of the HMIs which are toxic and chronic to human health. Identification of these water bodies prior to utilization is important. In detection of HMIs, electrochemical sensing may be proved to be a sensitive detection platform. In this case, an energy-efficient microwave method was applied to synthesize MOF of copper as the central metal ion and L-aspartic acid and Benzene tricarboxylic acid as the linkers. Aspartic acid is a biocompatible amino acid that is found naturally. In the synthesis of MOFs, microwave manufacturing provides a technique that is environmentally less polluting, stable in heat rate, low in reaction time, and high in yield. Good surface properties are exhibited by the MOF as synthesized. Ionic Liquid (EMIM TFSI) addition to MOF has enhanced its conductivity, HMI adsorption sites, and possible sensing platform window. Therefore, for electrochemical sensitive detection of HMIs, the synthesized MOF (L-asp-BTC-cu)/IL composite exhibited large active surface area, excellent charge transfer rate, enhanced conductivity, and time stability. FTIR and XRD were applied to study the synthesized composite. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were employed to identify the electrochemical response of MOF (L-asp-BTC-cu)/IL/GCE. Mercury (Hg) and lead (Pb) were quantified by square wave voltammetry (SWV). Results indicated that the lower limits of detection (LOD) and linear detection range for each of these three HMIs separately and in combination. Obtained limit of detection (LOD) for Pb (II) and Hg (II) were 0.17μM, and 0.36μM respectively.