Green Synthesis of Silver Nanoparticles using Indigenous Medicinal Plants: Physicochemical Characterization and Biomedical Evaluation

Abstract

Biological synthesis of silver nanoparticles (AgNPs) is a sustainable, eco-friendly alternative to toxic chemical methods to fulfil the urgent global need for advanced therapeutic nanomaterials. Bioactive phytochemicals of indigenous medicinal plants serve as excellent natural reducing and capping agents. This paper reports the rapid single-step green synthesis of AgNPs using an aqueous extract of indigenous plant. The progress of the bio reduction process was monitored by UV-Vis spectroscopy and the synthesised nanostructures were characterised systematically by UV-Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). Moreover, complete biomedical evaluations were carried out in vitro. The successful formation of AgNPs was confirmed by UV-Vis spectroscopy having a characteristic surface plasmon resonance peak at 430 nm.
FTIR analysis identified the main plant-derived phenolics and proteins responsible for long-term stabilisation of the nanoparticles without the use of chemical additives. The XRD and TEM confirmed the formation of highly stable spherical face centred cubic nanocrystals with optimum size distribution of 15 to 30 nm. Biogenic AgNPs showed significant dose-dependent antibacterial activity against Escherichia coli and Staphylococcus aureus in biomedical assays and was found to be much superior to the standard antibiotics.
In addition, they exhibited high free-radical scavenging activity in DPPH assays and showed selective, high-efficiency cytotoxicity against MCF-7 human breast cancer cells while preserving normal fibroblast viability. To summarise, this plant-mediated synthesis provides a scalable, economic and non-toxic approach to fabricate multifunctional bio-nanomaterials with significant translational potential in targeted antimicrobial therapy, oxidative stress management and advanced clinical nanomedicine.