Functionalised carbon nano spheres modified electrode for simultaneous determination of dopamine and uric acid

•Carbon nano spheres were functionalised.•Modified electrode was fabricated using the functionalised carbon nano spheres.•It was applied for the simultaneous determination of dopamine and uric acid.•Simple modification provides good sensitivity/selectivity ideal in real application.

In this paper we report the interaction of functionalised carbon nano spheres (FCNSs) with dopamine (DA), Uric acid (UA) and l-ascorbic acid (AA). FCNSs were characterised using SEM, AFM, spectroscopic and electrochemical measurements. Functionalised carbon nano spheres paste electrode (FCNSPE) has shown excellent preconcentration property of DA over its surface. UA also has also shown good electrochemical activity over the modified electrode. Parameters were optimised for the enhanced oxidation signal of DA in connection with simultaneous determination of DA and UA. An analytical method was developed for the simultaneous determination of DA and UA using the simple method of fabrication of electrode with detection limits (S/N of 3) of 10 nM and 42 nM for DA and UA respectively. Electrochemical oxidation signals of DA and UA were interference free from the oxidation of AA and other commonly occurring interfering agents. The method was applied for the determination of DA in spiked blood serum sample and for UA in real blood serum samples.

Graphical abstractThe functionalised carbon nano sphere modified carbon paste electrode has shown excellent sensitivity and selectivity for the simultaneous determination of dopamine and uric acid.Download high-res image (460KB)Download full-size image