rGO/ReO3 nano composite modified electrode for the ultra-sensitive determination of dopamine and uric acid

Abstract

Development of suitable modified electrode in generating the electrochemical signals from dopamine (DA), uric acid (UA) and ascorbic acid (AA) has remained challenging issue even after decades of research in the related field. Under the present investigation the perovskite type metal oxide nano particle has been used in the form of composite with the reduced graphene oxide (rGO) as the active material for sensing. The superior electrical conductivity of Rhenium oxide (ReO3) combined with the adsorptive and conducting nature of rGO has been utilised in enhancing the electrochemical responses form the molecules. Thin films of Nafion was used over the rGO/ReO3 composite materials for stabilization of the modification. The electron transfer property of the molecules has been evaluated from the cyclic voltammetry and electrochemical impedance measurements. The standard electron transfer rate constants have been obtained from the Laviron formulations of the cyclic voltammetry measurements. Simultaneous electrochemical response has been obtained from the three molecules over the rGO/ReO3 nano composite modified electrode, the analytical method has been developed with the detection limit (S/N = 3) of 0.08 nM, 0.06 μM and 0.89 μM for DA, UA and AA respectively. For simultaneous determination however, the determination of DA and UA has been proposed and the interference test was carried out through simultaneous detection of the signals of the molecules. The analytical method has been applied for the detection of analytical signals of DA and UA in synthetic serum samples through spiked recovery test.

Keywords

• Dopamine
• Uric acid
• Ascorbic acid
• ReO3
• rGO
• Voltammetry