Real-time detection of imidacloprid residues in water using f-MWCNT/EDTA as energetically suitable electrode interface

Abstract

Real-time assessment of an active ingredient imidacloprid in the water matrix is critically momentous in monitoring the levels of pesticide contaminants in water bodies. Conventional approaches predominantly deal with the detection of imidacloprid, relying on the purified analytical grade compound. Herein, we report an organic/inorganic composite (f-MWCNT/EDTA) integrated electrochemical sensor for the real-time analysis of analytical grade imidacloprid and extended the performance evaluation in agriculture-purpose imidacloprid compound used commercially by farmers. The choice of the electrode interface significantly supports the electrocatalytic activity towards imidacloprid due to the presence of appropriate energy levels, which are favourable for charge transfer processes validated with Density Functional Theory (DFT) calculations. Further, the performance of the sensor was evaluated in the aquatic environment using river water samples procured from seven different sampling sites and in tap water. The organic/inorganic composite-based electrochemical sensor shows a detection limit of 3.1 × 10−3 pM and three significant wide linear concentration ranges of 0.001–0.05 nM, 0.001–0.04 μM, and 0.001–0.004 mM with apparent interferent resistance. This work paves the way for the real-time environmental monitoring and quantification of imidacloprid by utilizing the highly effective f-MWCNT/EDTA composite catalytic layer.