Synthesis and characterization of <scp> SnO ₂ </scp> ‐ <scp>SA</scp> ‐ <scp>FA</scp> nanocomposite for anticancer (cervical cancer <scp>HeLa</scp> cells), antimicrobial (methicillin‐resistant <i>Staphylococcus aureus</i> , <i>Candida albic

Abstract This study reports the synthesis and characterization of a novel sodium alginate (SA) and folic acid (FA) functionalized tin oxide nanocomposite (SnO 2 ‐SA‐FA) and investigates its antimicrobial, antioxidant and anticancer properties. XRD analysis confirmed the tetragonal crystalline structure of SnO 2 , while the crystallite size decreased from 28.3 nm for pure SnO 2 to 22.1 nm after functionalization, indicating enhanced surface area and reactivity. UV–visible analysis revealed a reduction in bandgap energy from 3.6 to 3.4 eV, suggesting improved charge transfer capability. Photoluminescence studies showed green emission at 506 nm, indicating enhanced oxygen vacancy defects and reactive oxygen species (ROS) generation. The SnO 2 ‐SA‐FA nanocomposite demonstrated enhanced antimicrobial activity against methicillin‐resistant Staphylococcus aureus and Candida albicans , exhibiting zones of inhibition of 20 mm and 17 mm, respectively, with minimum bactericidal concentration values of 1600 μg mL −1 . Antioxidant studies revealed significantly improved 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity, reaching 83.23% at 100 μg mL −1 compared to 66.34% for pure SnO₂ nanoparticles. Cytotoxicity studies against HeLa cervical cancer cells demonstrated dose‐dependent anticancer activity, with the SnO 2 ‐SA‐FA nanocomposite exhibiting a lower IC 50 value (concentration required to inhibit 50% of cell viability) (40.6 μg mL −1 ) than pure SnO₂ nanoparticles (58.2 μg mL −1 ). Fluorescence microscopy confirmed enhanced apoptosis induction through ROS‐mediated oxidative stress and folate‐receptor‐targeted uptake. Furthermore, biocompatibility studies on L929 fibroblast cells showed cell viability above 80%, confirming low toxicity and favorable biological safety. These findings demonstrate that the SnO 2 ‐SA‐FA nanocomposite is a promising multifunctional nanoplatform for antimicrobial, antioxidant and targeted anticancer biomedical applications. © 2026 Society of Chemical Industry.