Investigation of the Interaction Between <scp>HSA</scp> and <i>Dioscorea pentaphylla</i> Leaf Extract‐Mediated Silver Nanoparticles Using Multi‐Spectroscopic and Calorimetric Techniques and Evaluation of Their Anti‐Biofilm Activity

This study aimed to develop a simple, rapid and eco-friendly method for the synthesis of silver nanoparticles (SNPs) employing the aqueous leaf extract of the medicinal plant Dioscorea pentaphylla as a natural and cost-effective reducing and stabilising agent. The synthesised Dp-SNPs were comprehensively characterised using UV-visible, FTIR, HR-TEM, AFM, DLS and XPS techniques. Their in vitro anti-biofilm activity was evaluated against both gram-negative V. cholerae and gram-positive S. aureus, demonstrating potent inhibitory effects against both bacterial strains. To elucidate the interaction between Dp-SNPs and human serum albumin (HSA), multi-spectroscopic techniques were employed. UV-visible and fluorescence analysis revealed a strong binding affinity of Dp-SNPs towards HSA. ITC experiment confirmed that the complexation process was spontaneous and primarily driven by hydrophobic forces. Fluorescence lifetime measurements indicated a static quenching mechanism, and CD spectroscopy suggested minimal alteration in the secondary structure of HSA upon conjugation with Dp-SNPs. Furthermore, an increase in the Zeta potential of Dp-SNPs after binding with HSA suggested improved colloidal stability of the protein-nanoparticle complex. These findings highlight the potential of Dp-SNPs as eco-friendly anti-biofilm agents and provide important insights into their interactions with serum proteins for biomedical applications.