Nickel oxide modified with sodium alginate and dopamine nanoparticles for enhanced antimicrobial, antioxidant, and anticancer activity against HepG2 cells.

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related mortality worldwide, while multidrug-resistant bacterial infections pose escalating health threats. To address these challenges, nickel oxide nanoparticles (NiO Nanoparticles) and sodium alginate-dopamine-NiO-SA-Dop nanoparticles (NiO-SA-Dop Nanoparticles) were synthesized and extensively characterized for multifunctional biomedical applications. X-ray diffraction revealed crystallite sizes of 40.6 nm (NiO) and 29.76 nm (NiO-SA-Dop). Transmission electron microscope analysis confirmed spherical morphology with reduced particle size upon modification, supporting improved surface properties. UV-visible spectroscopy showed band gap energies of 4.15 eV (NiO) and 4.44 eV (NiO-SA-Dop). Photoluminescence spectra indicated enhanced green emission in NiO-SA-Dop, suggesting a higher concentration of oxygen vacancies Linked to increased reactive oxygen species Generation. In functional assays, NiO-SA-Dop demonstrated superior free radical scavenging efficiency in the 2,2-diphenyl-1-picrylhydrazyl assay compared to NiO. Strong antibacterial activity was observed against Gram-negative pathogens including Pseudomonas aeruginosa, Klebsiella pneumoniae, Vibrio cholerae, Escherichia coli, and Shigella dysenteriae. Cytotoxicity assays against HepG2 cells yielded IC₅₀ values of 11.9 µg/mL for NiO and 10.3 µg/mL for NiO-SA-Dop, underscoring the enhanced anticancer efficacy of the modified nanoparticles. Overall, NiO-SA-Dop Nanoparticles exhibit promising antibacterial, antioxidant, and anticancer activities, making them strong candidates for advanced therapeutic development.