Cobalt hydroxide nanoparticles modified glassy carbon electrode as a biosensor for electrooxidation and determination of some amino acids

Abstract

The electrochemical behavior of some amino acids was investigated on cobalt hydroxide nanoparticles modified glassy carbon (CHM–GC) electrode in alkaline solution. The process of oxidation and its kinetics were established by using cyclic voltammetry, chronoamperometry techniques, and steady-state polarization measurements. The results revealed that cobalt hydroxide promotes the rate of oxidation by increasing the peak current, so these bimolecular reactions are oxidized at lower potentials. Cyclic voltammograms and chronoamperometry indicate a catalytic EC′ mechanism to be operative with electrogeneration of Co(IV) as the electrochemical process. Also, the process is diffusion controlled and the current–time responses follow Cottrellian behavior. This result was confirmed by steady-state measurements. The rate constants of the catalytic oxidation of amino acids and the electron transfer coefficients are reported.