Analysis of herbicide and its applications through a sensitive electrochemical technique based on MWCNTs/ZnO/CPE fabricated sensor

Abstract

The electrochemical performance of linuron (LNR) was studied by fabricating the carbon paste electrode (CPE) using multiwalled carbon nanotubes (MWCNTs) along with zinc oxide (ZnO) nanoparticles (MWCNTs/ZnO/CPE). The influence of electro-kinetic specifications involving steady heterogeneous rate, pH, sweep rate, temperature effect, transfer coefficient, accumulation time, activation energy, as well as the total number of protons and electrons participating in electro-oxidation of LNR has been established using voltammetric techniques like cyclic voltammetry (CV) and square wave voltammetry (SWV). These techniques were applied to investigate LNR in real samples such as soil including water samples. Over the 0.02 μM-0.34 μM ranges, a linear relationship was confirmed along with the limit of detection and quantification (LOD and LOQ) of the LNR. The synthesized ZnO nanoparticles were characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), and X-ray diffraction (XRD) analysis. The MWCNTs/ZnO/CPE sensor was considered sensitive for LNR detection because the sensor exhibited enhanced catalytic qualities with peak current in the involvement of 0.2 M phosphate buffer solution (PBS) of pH 6.0, attributed to the ultimate sensing performance of the sensor.

Keywords: Carbon paste electrode; Limit of detection; Linuron; Multiwalled carbon nanotubes; Soil and water analysis; Zinc oxide nanoparticles.