The Determination of Dopamine in Presence of Serotonin on Dopamine-Functionalized Electrochemically Prepared Graphene Biosensor

Abstract

Reported herein is the synthesis of electrochemically prepared graphene with dopamine (DA) functionalization and its application for the electrochemical detection of DA in presence of serotonin (5-HT). Graphene oxide-DA (GO-DA) resulted from the condensation reaction of GO and DA. It was characterized via several instrumental methods. The electrochemical reduction of GO-DA (ERGO-DA) has been employed for the electrochemical detection of DA without and with 5-HT. The electrochemical detection of DA has been verified through cyclic voltammetry, differential pulse voltammetry, and amperometric techniques in a 0.1 M phosphate buffer saline (PBS, pH 7.4). The influence of the accumulation time and pH of the PBS at ERGO-DA modified electrode for DA oxidation has been investigated. The interference has also been performed using interfering substances such as 5-HT, glucose, ascorbic acid, H2O2, and uric acid. The detection limit and linear range of DA have been calculated as 0.04 μM and 0.5–100 μM, respectively, (where s/n = 3) at the ERGO-DA modified electrode. The real sample analysis has done without any difficulty and this biosensor can be used up to 10 days.