Green Synthesis of Starch Nanoparticles Using Endemic Alyssum giosnanum Extract: Structural Characterization and Antioxidant, Antimicrobial, and Photocatalytic Applications

Abstract

Starch nanoparticles (SNPs) have attracted attention as sustainable nanomaterials, owing to their biodegradability, biocompatibility, and versatile application potential. In this study, SNPs were synthesized via a green approach using the endemic Turkish plant Alyssum giosnanum. The synthesized nanoparticles were characterized by XRD, FTIR, SEM, and zeta potential analyses to evaluate their structural and physicochemical properties. The SNPs exhibited an average particle size of 54.52 nm and a zeta potential of −20.5 mV, indicating good colloidal stability. XRD confirmed that the native A-type crystalline structure of starch was preserved after nanoparticle formation, while SEM revealed the transformation of starch granules into nanosized particles. The SNPs showed a water absorption capacity of 1.25 g/g and an oil absorption capacity of 0.61 g/g. Moderate antioxidant activity was observed in free radical scavenging assays. Antimicrobial evaluation demonstrated inhibition zones of 12.3, 14.4, 17.6, and 14.4 mm against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, and Candida albicans, respectively, with corresponding MIC₉₉ values of 304.87, 279.39, 244.19, and 222.65 µg/mL. Furthermore, under UV irradiation in the presence of H₂O₂, the SNPs achieved photocatalytic degradation efficiencies of 90.14% for methylene blue and 83.21% for rhodamine B, outperforming native starch and highlighting their potential as multifunctional nanomaterials.