One step facile synthesis of silver nanoparticles for the simultaneous electrochemical determination of dopamine and ascorbic acid

A silver nanoparticles modified carbon paste electrode (MCPE) was developed for the detection of dopamine using voltammetric techniques. The silver nanoparticles (AgNPs) were synthesized through a biological method by using leaf extract act as a reducing agent. The prepared AgNPs were characterized by X-ray diffraction (XRD) and UV-visible absorption spectroscopy (UV-vis). AgNPs are ideally suited for implementation in electrochemical applications due to their high electrical conductivity, high heterogeneous electron transfer rate, and low production cost. The electrochemical response of dopamine at a MCPE prepared with AgNPs is compared with the response of surfactant assisted synthesized AgNPs (S-AgNPs). The effect of pH suggests that an equal number of protons and electrons are involved in the electrochemical oxidation of dopamine. Differential pulse voltammetric technique (DPV) was used for the simultaneous determination of dopamine (DA), ascorbic acid (AA) and uric acid (UA). The peak potential separations for DA-AA and DA-UA were about 181 mV and 168 mV respectively, and the detection limit was 0.085 μM for DA. This work presents a simple approach to the determination of DA in the presence of AA and UA.