CuO@MWCNTs nanocomposite as non-enzyme electrochemical sensor for the detection of Malathion in seawater
Eman Serag, Azza El‐Maghraby, Nazly Hassan, Ahmed El Nemr
Abstract
ABSTRACT This study used an enzyme-free electrochemical technique to identify low quantities of Malathion in sea water samples. The working electrode was made from carboxylated multiwall carbon nano-tubes (c-MWCNTs) that were hybridised with copper oxide nanostructures (CuO NRs). Scanning electron microscopes (SEM) and transmission electron microscopes (TEM) were used to examine the morphology of the produced MWCNT and CuO NRs. X-ray diffraction was used to determine the crystallinity of produced materials. The electrochemical behavior of the non-enzymatic sensor was used to determine the presence of Malathion insecticides using linear sweep voltammetry (LSV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy and transmission electron microscope images showed that the produced MWCNT and CuO NRs were well-synthesized, and the CuO NRs were successfully connected to the growing MWCNT. The charge-transfer resistance (Ret) of the suggested c-MWCNT-CuO/GE and c-MWCNT-CuO/GE was lowered from 143 to 73.4Ω, showing improved electron transport and conductivity. The proposed c-MWCNT-CuO/GE had good electrochemical properties, such as a wide dynamic range (20–250 nM) and a low detection limit of 0.303 nM for the LSV approach. It had strong stability for 3 d, with a current response of 91 percent, high selectivity since the interference effect was less than 7%, and reproducibility was evaluated with five electrodes, yielding a standard deviation of 2.203%. The non-enzymatic sensor detected Malathion (organophosphorus insecticides) in aquatic environmental samples with recoveries ranging from 97% to 102% and relative standard deviations of less than 2%.