A Highly Sensitive Determination of Parathion Pesticide by Solid-Phase Extraction on a Silicon Carbide Nanoparticles Modified Electrode

This work reports a highly sensitive electrochemical sensor for the direct detection of pesticides. An electrode modification of silicon carbide nanoparticles has the function of pesticide pre-concentration by solid-phase extraction, thus improving the detection sensitivity and simplifying the process of operations. Electrochemical detection of parathion was investigated via cyclic voltammetry (CV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS), respectively. Under the optimized experimental conditions, the anodic peak currents of parathion by SWV are proportional to the concentrations of parathion in the linearity of I-p (mu A)= 0.00325 C (ng/ml) + 0.2162 (R-2=0.9985) ranging from 1x10(-9) to 1x10(-5) ng/ml with a detection limit of 5x10(-10) ng/ml (S/N=3). The sensor also exhibits good reproducibility and stability, and has been successfully used for the determination of parathion in real water samples with the recoveries between 99.8% and 101.2%.