Method development for determination of carbofuran using nanomaterial-modified screen-printed carbon electrode

Abstract

Determination of carbofuran by differential pulse voltammetry using graphene oxide and gold nanoparticles modified screen-printed carbon electrode (AuNPs/GO-SPCE) was developed. The optimization of the amount of graphene oxide, the concentration of gold nanoparticles and pH of supporting electrolyte were conducted by central composite design. The characterization of the developed electrode was carried out by scanning electron microscopy and energy-dispersive X-ray spectroscopy. Moreover, the microscopic electrode surface area and electrochemical behavior of carbofuran were studied by cyclic voltammetry. The operational parameters including type of supporting electrolyte, accumulation time and potential, modulation time and amplitude as well as hydrolysis process of carbofuran to carbofuran-phenol were optimized. Using differential pulse voltammetry on AuNPs/GO-SPCE under optimized conditions, the method exhibited 2 linear ranges of 1-30 (R2 = 0.9970) and 30-250 µM (R2=0.9991) with the limits of detection and quantification of 0.22 and 0.72 µM, respectively. Interfering other effects of eight pesticides were also studied. In addition, application of the proposed method to carbofuran determination in real cucumber and rice samples was achieved by standard addition method with acceptable recoveries of 92.8-107.2%. This sensitive and selective carbofuran detection method is very promising for simple and inexpensive analysis of agricultural samples.