Sargassum-derived nanomaterials: Biosynthetic mechanisms, advanced characterisation and multifunctional applications

Abstract

Nanotechnology has rapidly advanced through the development of nanoscale materials with unique physicochemical properties; however, concerns regarding the toxicity and environmental burden of chemically synthesised nanoparticles have accelerated the shift towards sustainable green synthesis methods. Sargassum species have emerged as promising biological platforms for producing metallic and metal oxide nanoparticles due to their rich polysaccharide, phenolic and pigment profiles, which provide strong reducing and capping capabilities. This review critically evaluates current progress in Sargassum-mediated nanoparticle biosynthesis, emphasising the biochemical mechanisms governing reduction, nucleation, growth and stabilisation. Advances in spectroscopic, microscopic and surface analytical techniques are examined to assess their ability to characterise nanoparticle morphology, composition and functional behaviour, while identifying methodological constraints that limit mechanistic interpretation. The multifunctional applications of Sargassum-derived nanoparticles across biomedical, agricultural, environmental, food and aquaculture sectors are analysed, highlighting their antimicrobial, antioxidant, anticancer and crop-enhancing potential. Despite expanding research, major gaps persist regarding protocol standardisation, molecular-level mechanistic insights, toxicity and biocompatibility assessment and scalable production. By integrating current evidence with these challenges, this review outlines the technological potential of Sargassum-based nanomaterials and proposes future research directions necessary for advancing sustainable innovation in green nanotechnology.