Pankaj Gupta
Indian Institute of Technology-Roorkee, India
Title: Nano gold modified screen printed carbon electrodes for simultaneous analysis of dopamine and 5-hydroxyindoleacetic acid
Biography
Biography: Pankaj Gupta
Abstract
In this study, a convenient, low cost and sensitive electrochemical method based on a disposable gold nano-particles modified screen printed carbon sensor (Au-NPs/SPCs) is described for the simultaneous determination of dopamine (DA) and 5-hydroxyindole acetic acid (5-HIAA). Field emission scanning electron microscopy (FE-SEM) and electrochemical impedance spectroscopy (EIS) were used to characterize the surface morphology of the Au-NPs modified SPCs. The electrochemical measurements were carried out using square wave voltammetry and cyclic voltammetry. The modified electrode exhibited good electro-catalytic properties towards the oxidation of DA and 5-HIAA and the electrochemical potential difference between DA and HIAA was measured to be 230 mV, which was large enough to determine DA and 5-HIAA individually and simultaneously. The anodic peak current of DA and 5-HIAA were found to be linear in the concentration range of 0.2–100 µM and 0.5-500 µM with the detection limit of 8 nM and 22 nM, respectively. The effect of common metabolites presents in human urine such as ascorbic acid, uric acid on electrochemical response of DA (10 µM) and 5-HIAA (20 µM) were also analyzed. It was found that 10-fold concentration of ascorbic acid does not interfere with the determination of DA and 5-HIAA, while higher concentration of UA (more than 60 µM), anodic peak signal for 5-HIAA start to broaden, but the peak of DA remained same. The analytical utility of developed protocol was evaluated by performing the recovery experiments in human urine and plasma samples of healthy persons, showing the recovery in the range 99.20-101.33%.