Electrochemical determination of L-dopa at cobalt hexacyanoferrate/large-mesopore carbon composite modified electrode

In this paper, a cobalt hexacyanoferrate/large-mesopore carbon modified glassy carbon electrode (CoHCF-LMC/GC) was simply fabricated by electrodepositing CoHCF film on LMC. The electrochemical behaviors of L-dopa at this modified electrode have been studied by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and amperometry. The results show that the CoHCF-LMC modified electrode exhibits efficiently electrochemical activity for L-dopa oxidation in 0.1 M PBS (pH = 7.4), and the quantitative determination of L-dopa is unperturbed by the ascorbic acid (AA). Amperometry results depict that the proposed sensor provides excellent performance towards the determination of L-dopa with a low detection limit of 1.7 x 10(-8) M in the wide concentration range from 1.0 x 10(-7) to 1.9 x 10(-3) M at +0.20 V versus Ag/AgCl. Moreover, the studied composite electrode exhibits a good reproducibility and long-term stability. Determination of L-dopa in commercial tablets and human blood serum with satisfying results was also investigated by the proposed composite electrode. (C) 2011 Elsevier B.V. All rights reserved.