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 × 10−8 M in the wide concentration range from 1.0 × 10−7 to 1.9 × 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.