Algae-assisted synthesis of nanoparticles

Abstract Green chemistry is considered as an ideal approach for the future prospect of nanomaterials. 70% of the earth’s surface is covered by a marine environment of which most of the area is still unexplored. In green chemistry, marine plants/algae/bio-nanofactories are utilized to orchestrate nanoparticles (NPs)/bimetallic NPs for biomedical and other applications. Algal extract (microalgae and macroalgae) intrinsically contains biomolecules, which leads to shell formation around the metal NPs to improve their biocompatibility. Different groups of algae such as phaeophyceae, rhodophyceae, chlorophyceae, and cyanophyceae have been explored for the amalgamation of metallic NPs. It is the ability of essential phytochemicals in algae (alkaloids, flavonoids, and terpenoids) which accumulate metal and reduce metal ions, thus making them superior contenders for synthesis by acting as sculpturing or capping agents, which directs particle growth. The effective biomolecules present in the algae influence the size, shape, composition, and physicochemical properties of NPs. Moreover, algae can grow even in polluted water sources and can synthesize NPs in these conditions without competing with the arable lands and freshwater bodies, thereby increasing their applicability to a wider extent. Holistically, this chapter will emphasize the comprehensive studies of algae-based nanoparticle synthesis in terms of their antimicrobial (antibacterial and antifungal) and anticancer activities.