Electrocatalytic Oxidation of Dopamine and Ascorbic Acid on Carbon Paste Electrode Modified with Nanosized Cobalt Phthalocyanine Particles: Simultaneous Determination in the Presence of CTAB

Abstract

Metallophthalocyanine (MPc) and its derivatives are well known as electrocatalysts to catalyze oxidation or reduction of some species, such as cysteine, nitric oxide. Their nanosized particles may display the potential optics, electronic, catalytic and structural properties. In this paper, carbon paste electrodes modified with nanosized cobalt phthalocyanine particles (denoted as Nano-CoPc-CPE) are fabricated. The electrocatalytic oxidation of dopamine (DA) and ascorbic acid (AA) on the Nano-CoPc-CPE was investigated by means of cyclic voltammetry. Nano-CoPc particles perform good electrocatalytic activity to DA and AA. The anodic peak potentials of DA and AA were separated with good sensitivity in the presence of cetyltrimethylammonium bromide (CTAB). The DA and AA can be simultaneously determined by using differential pulse voltammetry. On optimal conditions, the good linear response to DA and AA was observed in the range of 3.0 Â 10 À6 -1.0 Â 10 À4 M and 5.0 Â 10 À6 -3.0 Â 10 À4 M with the correlation coefficient of 0.9983 and 0.9978, respectively. Moreover, 100-fold AA did not interfere in the determination of DA. This method has been used to simultaneously determine DA and AA concentration in mixed drug samples with satisfactory results.

Preparation and characteristic of cobalt phthalocyanine modified carbon paste electrode for bisphenol A detection

“…The value of oxidation potential of Co II ? Co III is close to tetrakis benzylmercapto cobalt phthalocyanine, tetrakis dodecylmercapto cobalt phthalocyanine modified gold electrodes (around 0.10 and 0.20 V, respectively) [31] and cobalt tetra-2-mercaptopyrimidylphthalocyanine-appended modified glassy carbon electrode (0.09 V) [32], but lower than those obtained from CoPc, cobalt octabutoxyphthalocyanine modified glass carbon electrode (near 1.0 V) [22], CoPc modified vitreous carbon electrode (0.45 V) [33] and nanoCoPc modified CPE (0.58 V) [34]. The difference in the oxidation peak potential could attribute to the behavior of electrode material, structure of cobalt phthalocyanines, buffer system and supporting electrolyte.…”

“…Generally, electrocatalytic activity of CoPc is known to be related central metal atom [34]. Previous reports on the interaction of CoPc with oxidation substrate proposed the involvement of the Co(III)/Co(II) redox process [22,33,47].…”

Metallophthalocyanine-based molecular materials as catalysts for electrochemical reactions

“…(i) Carbon paste electrodes modified with nanosized CoPc particles with good catalytic behavior for the detection of DA and AA [271]. The anodic peak potentials of DA and AA appear well separated with good sensitivity in the presence of cetyltrimethylammonium bromide (CTAB), thus allowing their simultaneous detection.…”

Electrochemical Studies of an Iron Porphyrin Immobilized on Nb2O5/SiO2 and Its Application for Simultaneous Determination of Dopamine and Ascorbic Acid Using Multivariate Calibration Methodology

“…One strategy in order to improve the selectivity of the electrodes is to modify the electrode surfaces. Various attempts are reported in the literature to detect DA using electrochemical approaches such as carbon paste electrodes [10,11], selfassembled monolayers [12,13], sol -gel composite electrode [14,15], various Nafion modified electrodes [16,17] and carbon nanotubes [18,19], each one associated with its own advantages and limitations. Electrodes modified with metalloporphyrins have also been widely investigated because of their rich redox, catalytic and electrocatalytic properties [20 -24].…”