Speaker
Description
Polyphenolic compounds exhibit diverse redox properties that determine both their ability to reduce metal ions and their interactions with biologically relevant electroactive molecules. In this study, green synthesis of silver nanoparticles using grape seeds as natural polyphenol sources and the electrochemical behavior of quercetin in the presence of dopamine were investigated. Intact grape seeds served as reducing and stabilizing agents for AgNP synthesis from aqueous AgNO₃ solutions[1]. UV–VIS spectroscopy confirmed nanoparticle formation through the characteristic localized surface plasmon resonance band at 410–430 nm, while SEM analysis revealed predominantly spherical particles with diameters of 20–50 nm. The developed protocol represents a simple, eco-friendly approach aligned with Green Chemistry principles. The electrochemical properties of quercetin were examined in phosphate buffer (pH 7) using square-wave voltammetry. Quercetin exhibited a quasi-reversible redox process at approximately +70 mV versus Ag/AgCl, with diffusion-controlled behavior at low frequencies (1–10 Hz), whereas higher frequencies resulted in decreased responses due to kinetic limitations. Dopamine displayed a reversible redox transformation at approximately +0.20 V. Simultaneous measurements revealed weak but detectable interactions between quercetin and dopamine, while preserving sufficient peak separation for their individual identification. These findings highlight the importance of polyphenol redox chemistry in sustainable nanoparticle synthesis and biologically relevant electrochemical systems.
Keywords: dopamine; grape seeds; green synthesis; polyphenols; quercetin; redox interactions; silver nanoparticles; square-wave voltammetry.
References: [1] S. Lazarova, P. Apostoloski, R. Gulaboski, Monatshefte für Chemie - Chemical Monthly. 2023, 154, 1-9.