Phyto-fabricated silver nanostructure-mediated photocatalytic degradation of methylene blue, enhanced biocompatibility, biofilm eradication, and molecular docking against LasR bacterial signaling protein

The development of sustainable nanomaterials through plant-mediated synthesis has gained considerable attention as an alternative to conventional chemical approaches. In the present study, silver nanoparticles (AgNPs) were synthesized for the first time using a hydroalcoholic leaf extract of Talinum paniculatum and comprehensively evaluated for their biomedical and environmental applications. Formation of AgNPs was confirmed by a characteristic surface plasmon resonance peak at 422 nm. The biosynthesized nanoparticles were predominantly spherical with particle sizes ranging from 5 to 35 nm and an average diameter of approximately 22 nm, while XRD analysis revealed a highly crystalline face-centered cubic structure with a crystallite size of 20 nm. Dynamic light scattering showed a hydrodynamic size of 70 nm and a zeta potential of −33.1 mV, indicating good colloidal stability. The AgNPs exhibited broad-spectrum antibacterial activity and significantly suppressed Pseudomonas aeruginosa biofilm formation, achieving approximately 90.45 ± 3.56% inhibition at 200 μg/mL. Molecular docking against the quorum-sensing regulator LasR demonstrated stable binding within the ligand-binding pocket with a binding affinity of −5.02 kcal/mol, suggesting interference with quorum-sensing-mediated virulence. The nanoparticles displayed strong antioxidant activity, with 96.66 ± 3.14% DPPH radical scavenging and an IC₅₀ of 120 μg/mL. Hemocompatibility studies showed less than 10% hemolysis at 15.25 μg/mL. Furthermore, AgNPs induced marked cytotoxicity against MCF-7 breast cancer cells, producing 75.8 ± 2.56% growth inhibition at 250 μg/mL. Photocatalytic studies revealed 96.19% degradation of methylene blue within 70 min of sunlight irradiation. These findings establish T. paniculatum -derived AgNPs as multifunctional nanomaterials with promising prospects for antimicrobial, anticancer, and environmental remediation applications.