Abstract
The increasing demand for eco-conscious technologies to improve human health has led to the evolution of green nanomaterials as sustainable alternatives to conventional ones. This review highlights recent advances in the eco-friendly synthesis of nanomaterials, particularly ZnO, TiO2, graphene, and carbon-based nanostructures, using biological entities, green solvents, and mechanochemical techniques. These methods not only reduce environmental impact but also endow nanomaterials with enhanced electronic and optoelectronic properties, such as tunable band gaps, improved charge transport, and photo-responsiveness that can have a positive impact on human health. The integration of phytochemicals and microbial agents into synthesis protocols has yielded nanomaterials with superior stability, biocompatibility, and functionality, facilitating their application in energy devices, flexible electronics, biosensors, and environmental remediation. Furthermore, green-synthesized nanomaterials demonstrate reduced toxicity and improved biodegradability, as reported in comparative studies using zebrafish embryo and mammalian fibroblast models underscoring their potential in sustainable electronics. This review also addresses challenges in scalability, reproducibility, and regulatory compliance, while proposing future research directions toward smart, adaptive, and bio-integrated nanotechnologies that are better for human health.