Green synthesis and characterization of silver nanoparticles with different solvent extracts of Sesbania grandiflora (L.) Poiret and assessment of their antibacterial and antioxidant potentials

The Sesbania grandiflora is an important potential medicinal plant, medicinally used for anticancer and as an antioxidant, antimicrobial, anti-inflammatory, etc.; so for that, we focused the current study on different solvents (ethanol, methanol, and water) extracts of plant leaf for phytochemical analysis, GC-MS, synthesized silver nanoparticles characterized through UV (UV-visible inspection), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), atomic force microscopy (AFM), X-ray diffraction (XRD), and atomic force microscopy (AFM) biological application of nanoparticles for different types of antioxidant (DPPH, ABTS, OH, superoxide) and antibacterial activities. In result, UV visible spectrum analysis confirmed that the nanoparticle in 448-nm absorption, the surface Plasmon resonance band was observed, and functional groups are identified in FT-IR, which are aldehyde, isothiocyanate, and allene. Further, the nanoparticle size was confirmed by SEM analysis; it’s images a granular appearance and had particles that were 10–25 nm in size. The XRD pattern crystalline nature of AgNPs confirmed diffraction peaks at 77.53°, 64.33°, 44.33°, and 38.28°. AFM shows the majority of AgNP ranges (10–20 nm), and the secondary metabolites present in methanol (M) extract with more intensity; the uppermost content of total phenol content was found in M extract which showed (64.32±2.05 GAE) followed by ethanol (E) (62.89±1.54 GAE) and lowest in water (W) (61.87±1.96 GAE). In the GC-MS analysis, the 16 bioactive chemical compounds were found in M extract. In antioxidant analysis of the nanoparticles, in the DPPH method, the highest free radical scavenging was found in M which showed (93.55±2.13%; 500 μg/ml), followed by E (87.75±2.23); in ABTS assay, maximum scavenging in M was found to be 90.27±1.55, followed by E (81.75±1.35); superoxide showed that the uppermost in M obtained 92.15±1.41, followed by E (87.91±1.12), and in OH method the main amount in M is 90.45±1.42, followed by E (86.32±2.13). Ascorbic acid and quercetin were used as standards; IC 50 values are calculated, against multi-drug-resistant antibacterial pathogens including Salmonella enterica (15.67±0.11) and Staphylococcus aureus (10.54±0.27), tested with S. grandiflora silver nanoparticles which showed potential activity. Our findings concluded that the leaf extract of S. grandiflora acts as a bio-controlling agent with nanoparticles and is a potential tool for human society in related biomedical and food technology.