Biosynthesis of Silver Nanoparticles Using Leaves of Acacia Melanoxylon and their Application as Dopamine and Hydrogen Peroxide Sensors

Abstract

In work, we described a cost-effective and environmentally friendly technique for green synthesis of colloidal silver nanoparticles from an aqueous extract of fresh leaves of Acacia melanoxylon and their application as a dopamine and hydrogen peroxide sensor. The prepared silver nanoparticles were characterized using UV-Vis absorption spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), zeta-potential analysis, thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), etc. This method was found to be cost-effective, eco-friendly when compared to that of chemical and physical methods of nanoparticle synthesis. Silver nanoparticles modified carbon paste electrode (CPE) was fabricated for the detection of dopamine and hydrogen peroxide. The fabricated electrode showed an excellent sensitivity towards the oxidation of both dopamine (DA) and hydrogen peroxide (H2O2) in 0.1 M phosphate buffer (PBS) solution at pH 7. The effects of scan rate, and concentration of the modifier and analyte were studied by the cyclic voltammetric technique. The result exhibits good electrocatalytic activity, diffusion-controlled process and linear increase in peak current with different concentrations of dopamine and hydrogen peroxide.