Electrochemical Sensor Based on Silver Nanoparticles/Multi-walled Carbon Nanotubes Modified Glassy Carbon Electrode to Detect Cyanide in Food Products
Hongyuan Zhang, Dawei Sun, Tieping Cao
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 - , SO 3 2- , CH 3 COO - , I - , C 2 O 4 2- , Cl - , SO 4 2- , CO 3 2- , Ni +2 , Co 2+ , HPO 4 -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.