Synthesis of Silver Nanoparticles Using Seaweeds: A Review

Abstract

Nanotechnology has become an important field with applications in medicine, agriculture, environmental remediation, food technology, and pharmaceuticals. Among nanomaterials, silver nanoparticles (AgNPs) have received considerable attention due to their unique physicochemical properties and diverse biological activities. Conventional synthesis methods often involve toxic chemicals and high energy consumption, creating environmental concerns. Therefore, green synthesis approaches have emerged as sustainable alternatives. Seaweeds (marine macroalgae) are promising resources for the eco-friendly synthesis of AgNPs because they contain bioactive compounds such as polysaccharides, proteins, phenolics, flavonoids, pigments, and vitamins that act as natural reducing and stabilizing agents.Recent studies have reported the successful synthesis of silver nanoparticles using extracts from green, brown, and red seaweeds. These nanoparticles exhibit significant antimicrobial, antioxidant, anticancer, antiinflammatory, and catalytic activities. Characterization techniques including UV–Visible spectroscopy, FTIR, XRD, SEM, TEM, and DLS are commonly used to confirm nanoparticle formation and evaluate their physicochemical properties. Seaweed-mediated synthesis offers advantages such as simplicity, costeffectiveness, environmental friendliness, and scalability. This review highlights recent advances in seaweed-based AgNP synthesis, mechanisms of nanoparticle formation, characterization methods, biological activities, and industrial applications. It also discusses challenges and future prospects for large-scale production and commercialization, emphasizing the role of marine bioresources in sustainable nanotechnology.