Simultaneous electroanalysis of dopamine, paracetamol and folic acid using TiO2-WO3 nanoparticle modified carbon paste electrode

Abstract

In this study, mixed titanium oxide and tungsten trioxide nanoparticles (TiO2-WO3NPs) were prepared and characterized by different characterization techniques. The prepared materials TiO2-WO3NPs were used as modifiers in carbon paste electrode (TiO2-WO3NPs/MCPE) to study the electrochemical behaviour of dopamine (DA) in phosphate buffer solution (PBS) at pH 7.4 by using cyclic voltammetric (CV) technique. The TiO2-WO3NPs/MCPE shows enhanced electrocatalytic activity compared to bare CPE. As a result, the TiO2-WO3NPs/MCPE was used for further electrochemical studies. The effect of pH proposed that an equal number of electron and proton are involved in the electrochemical reaction of DA. The DA concentration determination was in the range 2 × 10−6 M to 18 × 10−6 M and the limit of detection (LOD) and limit of quantification were found to be 10.18 nM and 34.32 nM. From the scan rate study the oxidation of DA was found to be adsorption controlled and simultaneous detection of DA, PA and FA were well separated in CV and differential pulse voltammetric (DPV) technique. Moreover the stability and reproducibility of TiO2-WO3NPs/MCPE at DA was studied and furthermore successfully demonstrated for the detection of DA in blood serum and injection samples.