Design and Synthesis of Novel Electrochemical Sensing Platform for Water Remediation

Abstract

Heavy metal ions (HMIs) contamination of fresh water bodies has raised concern all over the world. Among HMIs, arsenic (As), lead (Pb) and mercury (Hg) are toxic and chronic to human health due to their bioaccumulation and non-degradability. Sensitive detection of these water bodies is very much necessary before utilization. Electrochemical sensing may be proved to be sensitive detection platform for HMIs detection. Herein, MOF of L glutamic acid as linker and copper as central metal ion was prepared by energy efficient microwave method. Glutamic acid is naturally available, biocompatible amino acid. Microwave production provide energy efficient, stable heating rate, lower reaction time, high yield and less environmental pollution method for MOF preparation. Excellent surface properties shown by as prepared MOF. Conductivity of MOF, adsorption sites for HMIs and potential window for sensing platform have enhanced by incorporating Ionic liquid (EMIM TFSI) with MOF. Therefore as prepared MOF (L-glu-cu)/IL composite exhibited high active surface area, good charge transfer rate, enhanced conductivity and stability over time for sensitive electrochemical detection of HMIs. Synthesized composite was characterized by XRD and FTIR. Electrochemical behavior of MOF (L glu-cu)/IL@GCE was identified by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Square wave voltammetry (SWV) was used for detection of arsenic (As), lead (Pb) and mercury (Hg). Results demonstrated that linear detection range and lower limits of detection (LOD) for these three HMIs individually and simultaneously. Obtained limit of detection (LOD) for As (III), Pb (II) and Hg (II) were 2.69ngL-1, 2.201ngL-1 and 3.323ngL-1 respectively.