Phytochemical-Mediated Synthesis of Silver Nanoparticles: Mechanisms, Characterization and Biomedical Applications

Abstract

Silver nanoparticles (AgNPs) have gained considerable attention in nanotechnology because of their unique physicochemical, antimicrobial, antioxidant, anti-inflammatory, and anticancer properties. Conventional methods of AgNP synthesis often involve toxic chemicals, high energy requirements, and environmentally hazardous by-products. In contrast, phytochemical-mediated synthesis, commonly referred to as green synthesis, has emerged as a sustainable and eco-friendly alternative for nanoparticle production. Plant-derived bioactive compounds such as flavonoids, phenolics, alkaloids, terpenoids, proteins, and polysaccharides act as natural reducing, stabilizing, and capping agents during nanoparticle formation. This review explores the mechanisms involved in the phytochemical-mediated synthesis of silver nanoparticles and highlights the role of medicinal plant extracts in nanoparticle production. The synthesis process involves the reduction of silver ions (Ag⁺) into metallic silver (Ag⁰) through electron donation from phytochemicals, followed by nucleation, growth, and stabilization of nanoparticles. Various characterization techniques including UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Light Scattering Review of International Geographical Education (DLS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Zeta Potential Analysis are discussed for evaluating nanoparticle properties. The biomedical applications of phytosynthesized AgNPs have expanded significantly in recent years. These nanoparticles exhibit broad-spectrum antimicrobial activity against bacteria, fungi, and viruses through membrane disruption, reactive oxygen species generation, and interference with cellular metabolism. Additionally, AgNPs demonstrate promising antioxidant, anti inflammatory, wound-healing, drug delivery, and anticancer properties. Their ability to enhance therapeutic efficacy while reducing toxicity has made them attractive candidates for next generation nanomedicine. Overall, phytochemical-mediated synthesis offers a green, cost-effective, and scalable strategy for producing biocompatible silver nanoparticles. Continued research into synthesis optimization, mechanistic understanding, and clinical translation is expected to further expand the biomedical potential of green-synthesized AgNPs.