Cationic Surfactants- Assisted Synthesis of ZnO Nanoparticles and Their Modified Carbon Paste Electrode for Electrochemical Investigation of Dopamine

ZnO nanoparticles were synthesized using zinc nitrate, cetyltrimethyl ammonium bromide and sodium hydroxide in co-precipitation method. The obtained particles were characterized using X-ray diffractometer (XRD), UV-Vis absorption spectroscopy (UV-Vis), Infrared absorption spectroscopy (IR) and Scanning electron microscopy (SEM). The ZnO nanoparticles are used for the preparation of modified carbon paste electrode (MCPE). The MCPE was applied for electrochemical investigation of dopamine (DA) which exhibits enhancement of current response with reduction of over potential for investigation of DA at pH.7.0. The effect of pH range from 5.5 to 8.0 was studied and the redox peak was pH dependent with a slope of 53 mV/pH. The effect of scan rate shows adsorption controlling process and the electrocatalytic currents increases linearly with increase in DA concentrations in the ranges of 0.1-20 μM. The detection limit was found to be 0.3×10-7 M.