Kundan Samal
Nanotechnology has emerged as a promising field for developing sustainable materials with wide-ranging environmental and pharmaceutical applications. Among various approaches, green-synthesized nanoparticles (GSNPs) has gained significant attention as an eco-friendly, cost-effective, and bio-compatible alternative to physical and chemical synthesis methods. GSNPs utilize biological entities such as plant extracts, bacteria, fungi, algae, and biomolecules as reducing and stabilizing agents, eliminating the need for toxic chemicals. This review critically discusses recent development in the synthesis mechanisms, influencing factors, and characterization techniques of GSNPs. Special emphasis is given to the role of parameters such as pH, temperature, reaction time, extract concentration, and metal ion concentration in controlling NPs size, morphology, crystallinity, and stability. Furthermore, the review highlights major environmental applications including wastewater treatment, air pollution control, and soil remediation, where green NPs exhibit excellent adsorption, photocatalytic, and pollutants degradation properties. In addition, pharmaceutical applications such as drug delivery, antimicrobial activity, anticancer therapy, antioxidant, anti-inflammatory activity, and biosensing are comprehensively summarized. Despite remarkable advancements, challenges related to scalability, toxicity assessment, and long-term environmental impact remain critical. Overall, this review provides valuable insights into the recent advancement and future perspectives of GSNPs for sustainable environmental and biomedical technologies.