Biogenic synthesis of iron nanoparticles using Laurencia papillosa: characterization, optimization, and dual applications in heavy metal removal and potential cancer treatment

The present study explores the biogenic synthesis of iron nanoparticles (FeNPs) using the red marine alga Laurencia papillosa, aiming to evaluate their dual potential in environmental remediation and cancer treatment. The FeNPs were synthesized under optimized conditions determined by response surface methodology (RSM), pH 7.0, 20 g/100 mL algal concentration, and 24 h, ensuring maximum yield and reproducibility. The synthesized FeNPs were characterized using X-ray Diffraction (XRD), FTIR, TEM, SAED, SEM, EDAX, and zeta potential analysis, revealing spherical, polydispersed particles with sizes ranging from 10.17 to 19.99 nm and a zeta potential of + 7.4 mV, indicating moderate stability. Optimization of synthesis conditions using a response surface methodology (RSM) model identified pH 7.0, 20 g/100 mL algal concentration, and 24 h as optimal for maximum nanoparticle yield. The FeNPs demonstrated remarkable efficacy in removing heavy metals from aquaculture wastewater, with removal efficiencies of 96.4% for Fe, 58.3% for Mn, and 23.1% for Zn. Additionally, in vitro cytotoxicity assays demonstrated dose-dependent inhibitory effects against Human liver (HepG2) and Breast (MDA-MB-231) cancer cell lines, confirming the potential biomedical application of these eco-friendly FeNPs. These findings highlight the unique capability of L. papillosa-mediated FeNPs as multifunctional nanomaterials, bridging sustainable environmental remediation with cancer therapeutics, offering promising prospects for sustainable nanotechnology in both environmental and biomedical fields. Overall, the study demonstrates that L. papillosa derived FeNPs combine optimized green synthesis, effective heavy metal removal, and notable anticancer activity, underscoring their potential as cost-effective and environmentally sustainable multifunctional nanomaterials.