DOI: https://doi.org/10.55373/mjchem.v28i3.186

Keywords: Nanomaterials, CuO NPs, algae, green synthesis, environmental sustainability

Abstract

Copper oxide nanoparticles (CuO NPs), renowned for their antimicrobial, antiviral, and antioxidant properties; have attracted substantial attention across diverse scientific and industrial domains. Their high surface-area-to-volume ratio, nanoscale size, and unique physicochemical characteristics position them as cost-effective alternatives to noble metals in applications such as drug delivery, environmental remediation, catalysis, wound healing, antimicrobial coatings, and biosensors. However, conventional CuO NP synthesis often involves toxic reducing agents, energy-intensive processes, and hazardous by-products—raising critical concerns regarding sustainability and environmental safety. To address these challenges, recent research has shifted toward green synthesis approaches using biological feedstocks. Among the most promising eco-friendly strategies are plant-mediated and algae-mediated synthesis techniques, which utilize naturally derived reducing and stabilizing agents to fabricate CuO NPs under mild, non-toxic conditions. Various algal species—including Chlorella vulgaris, Sargassum muticum, Ulvalactuca, and Spirulina platensis—offer abundant intracellular and extracellular metabolites (e.g., polysaccharides, proteins, phenolic) that drive bio-reduction and nanoparticle stabilization. Algae are regarded as more superior as compare to plant extract in the bio-fabrication of the nanoparticles due to their rich and consistent composition of the bioactive molecules that efficiently function as reducing and capping agents, leading to the faster nanoparticles formation with improved control over size, morphology and dispersion. Recent advancements include the implementation of continuous flow bioreactor systems, hybrid green-chemical methods, and scalable synthesis protocols that enhance nanoparticle yield, size control, and functional performance. Despite these promising developments, key challenges remain-such as standardizing biosynthetic conditions, ensuring reproducibility across scales, and fine-tuning particle morphology.