Algae and cyanobacteria-mediated biosynthesis of metal/metal oxide nanoparticles and their potential applications in food packaging

With a growing global emphasis on sustainability and eco-friendly practices, biosynthesis of nanoparticles has emerged as a pioneering alternative to conventional chemical-based synthesis methods. In this context, algae and cyanobacteria have been used as renewable biomass resources, providing an economically viable, environmentally benign, and easily scalable platform for nanoparticle production. Algae and cyanobacteria extracts comprise various functional macromolecules and metabolites that not only reduce the metal salts to form nanoparticles but also form a surface capping, aiding their stabilization and imparting additional functionality. Algae and cyanobacteria have successfully mediated the synthesis of diverse nanoparticles, especially metal and metal oxides, demonstrating exceptional functional and biological properties. Remarkably, these biosynthesized nanoparticles often rival or even surpass the performance attributes of chemically synthesized counterparts, underscoring their potential in various industrial applications. One particularly promising application lies in the food packaging sector, where nanoparticles serve as multifunctional fillers in biopolymer matrices, significantly enhancing film characteristics. Conventional chemically synthesized nanoparticles, however, have raised critical safety and environmental concerns, intensifying the demand for greener alternatives. This comprehensive review uniquely addresses these challenges by focusing explicitly on algae and cyanobacteria-mediated nanoparticle synthesis and meticulously discusses their prospective applications in food packaging. These biosynthesized surface functionalized nanoparticles not only address safety concerns by displaying enhanced biocompatibility and reduced cytotoxicity but also can provide additional functional properties like antioxidant activity to the food packaging materials, emphasizing their potential to extend food shelf-life and ensure consumer safety.