Green Synthesis of Silver Nanoparticles using Bryophyllum pinnatum (Lam.) and monitoring their antibacterial activities

The increasing demand for sustainable biomedical solutions has driven ongoing research toward green nanomaterial synthesis. The present study reported an eco-friendly, cost-effective protocol for synthesizing silver nanoparticles (AgNPs) using the aqueous leaf extract of the ethnomedicinal plant Bryophyllum pinnatum (Lam.). The reduction of Ag⁺ ions to metallic silver was confirmed by a distinct color transition from pale yellow to brown. Fourier Transform Infrared Spectroscopy (FTIR) analysis has been performed, validating the dual role of plant phytoconstituents. Significant absorption bands at ~3400 cm⁻¹ (O–H stretching) and ~1635 cm⁻¹ (C=O stretching) indicated that phenolic compounds, flavonoids and proteins were present within the extract. These functioned as effective bio-reductants and stabilizing capping agents for the nanoparticles. Further, antibacterial potential of the synthesized AgNPs was assessed against Gram-negative (Pseudomonas aeruginosa MTCC 2295 and Escherichia coli MTCC 5704) and Gram-positive (Staphylococcus aureus MTCC 3160, and Bacillus subtilis MTCC 121) bacteria by using agar-well diffusion method. The AgNPs was exhibited significantly greater antibacterial activity than the crude leaf extract. B. subtilis MTCC 121 has shown highest susceptibility with an inhibition zone of 21 ±1.9 mm while E. coli showed a zone of 20 ±1.7 mm. The AgNPs was exhibited slightly lower inhibition zones than standard antibiotic Ciprofloxacin (25–28 mm). However, their broad-spectrum efficacy was attributed to the synergistic interplay between the nanoparticles specific surface area and bioactive capping agents. The two-way ANOVA showed a highly significant effect of treatment type (p < 0.001) was represent that the synthesised B. pinnatum (Lam.) extract-derived AgNPs have superior antibacterial activity compared with the B. pinnatum (Lam.) extract alone. There was also a significant difference among bacterial strains (p < 0.05) indicates wide-ranging susceptibility. The prospects of the present findings endorsed B. pinnatum (Lam.) extract-derived AgNPs as promising candidates for developing natural and effective antimicrobial agents. Keywords: Silver Nanoparticles (AgNPs), Bryophyllum pinnatum (Lam.), Green Synthesis, Antibacterial Activity, Eco-friendly