Lentil-Husk-Mediated Green Synthesis of Silver Nanoparticles: Characterization and Antibacterial Activity

Plant-based preparation of nanomaterials has become a recent global research focus due to its cost-effectiveness, sustainability, and environmentally friendly approach. This study aims to synthesize silver nanoparticles (HAgNPs) using red lentil husk aqueous extract (LHE) and to assess its antibacterial activity. Synthesized HAgNPs were analyzed by ultraviolet-visible spectroscopy (UV-vis.), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) analysis. The antibacterial efficacy of synthesized HAgNPs was investigated against Staphylococcus aureus (ATCC No: 25923), Enterococcus faecalis (ATCC No: 29212), Klebsiella pneumoniae (ATCC No: 700603), and Shigella sonnei (ATCC No: 25931) at varying concentrations via the agar well diffusion scheme. The UV-vis absorption maximum observed around 420 nm directed the creation of HAgNPs. The shifting of peak positions in the FTIR spectrum of the synthesized HAgNPs compared to the FTIR spectrum peak positions of LHE indicated the involvement of biomolecules present in LHE in reducing silver ions to metallic silver. XRD examination of the prepared sample suggested face-centred cubic crystals of the HAgNPs. The average particle dimension of prepared HAgNPs was 8.9 nm by the Debye–Scherer equation. An FESEM examination of the synthesized HAgNPs revealed spherical morphology, while the EDX study showed that silver (Ag0) was the predominant component, comprising 62.3% by weight. The synthesized HAgNPs displayed a higher DPPH radical scavenging capacity (IC50 = 38.87 ± 3.52 µg/mL) than that of LHE (IC50 = 65.27 ± 1.17 µg/mL). The prepared HAgNPs exhibited significant antibacterial efficacy against some human pathogen bacteria at lower concentrations. Hence, the present study highlights an environmentally benevolent and economical synthetic approach to the preparation of HAgNPs and its potential utility for the production of biomedical products.