Electrochemical behavior of some organic molecules at tailored nanostructured modified electrodes

Abstract

Glucose and ascorbic acid (AA) electrooxidation are examined at nickel nanoparticles (nano-Ni) and cobalt nanoparticles (nano-Co) modified binary catalyst, fabricated in a certain order onto glassy carbon (GC) electrode. Either nano-Ni was deposited at first then followed by nano-Co or the reverse. Characterization of the modified electrodes were achieved morphologically and voltammetrically. The electrochemical response of the nano-Co modified electrodes critically depends on the modification of the underlying substrate. Deposition of nano-Co on a pre-deposited nickel subjected to electrooxidation, designated as nano-Co/NiOx/GC, resulted in a significant catalysis of glucose oxidation. The nano-Co/NiOx/GC electrode is utilized for the simultaneous analysis of glucose and ascorbic acid using square wave voltammetry (SWV). The linear dynamic ranges for the two species were determined. The limit of detection (LOD) and limit of quantification (LOQ) values were calculated and founded 0.176 and 0.528 μM for AA and 0.066 and 0.199 μM for glucose. Also, the precision of the developed method was evaluated by determining the relative standard deviation (RSD) and found less than 2.3%.