Biosensors & Bioelectronics

Electrochemical Detection of Dopamine in Presence of Serotonin and Ascorbic acid at Tetraoctyl ammonium bromide Modified Carbon Paste Electrode: A Voltammetric Study

Abstract

Shankar SS, Shereema RM, Prabhu GRD, TP Rao and Kumara Swamy BE*

An electrochemical simultaneous evaluation of dopamine (DA), serotonin (5-HT) and ascorbic acid (AA) in phosphate buffer solution (PBS) of pH 7.4 was attempted using a cationic surfactant, tetraoctylammonium bromide, modified carbon paste electrode (TOABMCPE). At the modified electrode, a well-defined redox peak with a great enhancement in current was witnessed. The oxidation of DA was found to be greatly pH dependent. The TOAB fabricated electrode overcomes the problem of resolution of DA with the coexisting species, AA and 5-HT. Simultaneous studies through cyclic voltammetric and differential voltammetric techniques gave excellent results with a great potential difference between DA-AA and DA-5-HT. The detection limit of the modified electrode was found to be 0.019 μM with the aid of amperometry. The developed sensor was applied for the detection of DA in injection samples.