Fabrication of Methyl Parathion Electrochemical Sensor Based on Modified Glassy Carbon Electrode with Graphitized and Carboxylated Multi-Walled Carbon Nanotubes Decorated with Zirconia Nanoparticles

Abstract

Herein, we modified the glassy carbon electrode (GCE) by using the nanocomposite of graphitized and carboxylated multi-walled carbon nanotubes (GR-MWCNTs-COOH) and zirconia (ZrO2) nanoparticles for the fabrication of GR-MWCNTs-COOH/ZrO2/GCE sensor. GR-MWCNTs-COOH had high electrical conductivity, large specific surface area, and good hydrophilicity. ZrO2 nanoparticles possessed strong affinity toward the phosphorus groups on methyl parathion (MP) molecules, which contributes to the enrichment of MP on the modified GCE surface. The fabricated GR-MWCNTs- COOH/ZrO2/GCE sensor exhibited excellent electrochemical sensing performance for the determination of MP due to the synergistic effect of GR-MWCNTs-COOH and ZrO2. Under the optimal conditions, the GR-MWCNTs-COOH/ZrO2/GCE sensor could show a low limit of detection of 0.00135 µM in linear MP concentration range of 0.01-10 µM. Moreover, the fabricated sensor presented good reproducibility, repeatability, and selectivity, which could promote the practical application of MP sensor.