Electrochemical sensor based on silver nanoparticles/Multi-walled carbon nanotubes modified glassy carbon electrode to detect cyanide in food products

Abstract

In this study, silver nanoparticles/carbon nanotubes (Ag NPs/CNTs) was successfully synthesized on the surface of glassy carbon (GC) electrode using a facile chemical technique to evaluate determination of cyanide as a toxic substance in food products. The structural properties of synthesized CNTs and Ag NPs/CNTs were studied by scanning electron microscope, energy dispersive X-Ray and X-Ray diffraction analyses. The voltammetric and amperometric techniques were used for electrochemical studies of modified electrodes. The structural studies showed high density, porosity and aspect ratio of the Ag NPs/CNTs electrodes. The cycle voltammetric studies of Ag NPs/CNTs/GC electrode showed sharp and stable oxidation peak at 0.75 V in pH 7 for cyanide. Amperometry results exhibited that Ag NPs/CNTs/GC electrode was sensitive, selective and stable to determinate cyanide. The linear range, sensitivity, and detection limit of modified sensor were 0.1 to 210 μM, 0.7192 μA/ μM and 4 nM, respectively which were better values than those obtained in previous researches. Study on the interfere effect of Br-, SO32-, CH3COO-, I-, C2O42-, Cl-, SO42-, CO32-, Ni+2, Co2+, HPO4-2, F-and Zn+2 analytes showed that there was not any interfere in determination of cyanide on Ag NPs/CNTs/GC electrode surface. The recorded amperometrogram results of real sample showed the modified electrode was successfully applied for cyanide detection in apricot juice.