Optimized green synthesis of silver nanoparticles from guarana seed skin extract with antibacterial potential
Year: 2025
Type: article
Abstract: This study optimizes the green synthesis of silver nanoparticles (AgNPs) using seed skin extract of guarana ( Paullinia cupana ) as a natural stabilizing and reducing agent. Employing a Taguchi design, nine experiments were conducted across three levels for four key factors: reaction temperature, pH, silver nitrate concentration, and guarana seed skin extract concentration to minimize AgNP size. Optimal conditions – pH 11, 5 mM silver nitrate, 50°C reaction temperature, and 1% (m/v) guarana extract – produced quasi-spherical AgNPs with an average size of ∼26 nm. Chemical analysis revealed caffeine as the main organic compound and potassium oxide as the primary inorganic component. UV-vis spectra showed an absorption peak at 438 nm, and X-ray diffraction confirmed typical AgNP peaks. Further analysis identified polyphenols, alkaloids, and flavonoids as reducing and stabilizing agents. A high AgNP concentration (180.0 ± 0.2 ppm) was confirmed through ICP-OES, and AgNPs demonstrated a significant antibacterial activity against Escherichia coli and Staphylococcus aureus , with a minimum inhibitory concentration of 50 μg·mL −1 . This study underscores the sustainability of green synthesis as a promising alternative to traditional nanoparticle production methods.
Source: Green Processing and Synthesis
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,808
OpenAlex ID: W4406169746