Interrogating the Electrochemical Potential of Senna obtusifolia Mediated Biosynthesized Silver Nanoparticles

Abstract

Hazards and toxicity associated with the physical and chemical synthesis protocol of metal nanoparticles has recently led researchers to seek alternative routes that is eco-friendly, cheap and fast; the green chemistry approach where plant extracts and microorganisms are used in the reduction of the metal salt is fast gaining popularity in the field of nanobiotechnology. However, controversy still trails acceptability; furthermore, electrochemical studies on these metal nanoparticles are limited. In this study, silver nitrate was reduced to its “nano silver form” through a one-step synthesis protocol using leaf extract of Senna obtusifolia . The usual microscopic and spectroscopic techniques such as UV-vis., FTIR, SEM, AFM and XRD were used to confirm the formation of silver nanoparticles. Electrochemical characterization using cyclic voltammetry and impedance spectroscopy further reveals the formation of silver nanoparticles via a redox process of Ag 1+ to Ag 0 with a formal potential value of 0.61 V vs. Ag|AgCl 3 M KCl.