Development of an electrochemical sensor based on the combination of copper‐based metal‐organic framework and gold particles for glyphosate detection in water

Abstract This work develops a sensing platform based on the combination of copper‐based metal‐organic framework with 1,3,5‐benzenetricarboxylic acid (CuBTC) and gold particles (AuPs), taking advantage of the materials’ properties, such as high porosity of CuBTC and high conductivity of AuPs and their synergistic effect. First, AuPs were electrodeposited onto a glassy carbon electrode (GCE), followed by the drop‐cast of CuBTC onto AuPs/GCE. The morphology and element presence of CuBTC/AuPs/GCE were examined by SEM and EDX. The bare and modified electrodes were tested by electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry. The results demonstrate that CuBTC/AuPs/GCE improves the electron transfer and offers a more distinct current difference, approximately 1.8 times higher than CuBTC/GCE, making it more effective for glyphosate determination. The sensor shows good performance with high sensitivity of 1.1 10 9 µA mM cm −2 and low limit of detection of 44 pM, high selectivity, and good reproducibility with an RSD of 2.2%. Real samples before and after spiking were analyzed using sensors and liquid chromatography‐mass spectrometry (LC‐MS/MS). Both results aligned with each other with recoveries of 100% and 103% for sensors and MS/MS analysis, respectively. The developed sensors could be successfully applied for the analysis of glyphosate concentration in environmental samples.