Electrochemical sensor for the detection of imidacloprid using novel Cu-tetrazole MOF

Designing sensitive and rapid sensing platforms for detecting pesticide residues is crucial for ensuring environmental and food safety. In this work, we report the synthesis of a novel Cu-Tetrazole Metal-Organic Framework referred to as KU-1 and its utilization for the development of an electrochemical sensor for the detection of imidacloprid (IMD) residues in food samples. The MOF structure consists of Cu ions and tetrazole ligands that extend to form 2D layers, which are further pillared by tetrazoles to create a 3D network. The KU-1 exhibits high stability, retaining crystallinity in various organic solvents and a range of pH, with thermal stability up to ∼300°C. The electrochemical sensing of IMD at KU-1 modified screen-printed electrode was investigated in detail, demonstrating the material's high electrocatalytic performance. The developed sensor allowed imidacloprid detection in the linear range of 0.1–10 μM with a detection limit of 0.089 μM and showed excellent selectivity for IMD against other pesticides. Detection of IMD residues was successfully validated in rice and tomato sample extracts and had a remarkable recovery of 97–101%, showcasing the electrode's practicality and reliability. This study highlights the potential of KU-1 as a promising material for constructing high-performance electrochemical sensors.