Priyadharshini, S.S.PriyadharshiniKarnan, M.M.KarnanAyyanar, M.M.AyyanarJenipher, C.C.JenipherArun ThirumuruganChidhambaram, N.N.Chidhambaram2026-07-072026-07-072026COORDINATION CHEMISTRY REVIEWS, 555, 217637 (2026). https://doi.org/10.1016/j.ccr.2026.2176370010-85451873-3840https://hdl.handle.net/20.500.12740/24711Oxidative stress and its associated complications pose serious threats to human health, demonstrating the pressing need for effective redox-active materials. This study presents the biogenic synthesis of a redox-active Copper oxide/Magnesium oxide (CuO/MgO) nanocomposite using Citrus limonium extract and evaluates its antibacterial, antioxidant, and antidiabetic activities, along with CuO nanoparticles for comparison. X-ray diffraction (XRD) analysis divulges the interwoven CuO and MgO phase in a single matrix with a crystallite size of 44 nm. Fourier transform infrared (FTIR) spectra expose the vibrational bands at 864, 678, and 570 cm-1, corresponding to Cu-O, Mg-O, and Cu-O-Mg. Optical analysis reveals a bandgap energy of 1.47 eV for the CuO/MgO composite, higher than 1.29 eV observed for CuO nanoparticles, indicating the improved visible-light absorption. Morphological examination reveals irregular aggregates with porous surface texture of the CuO/MgO composite. X-ray photoelectron spectroscopy (XPS) analysis substantiates the Cu2+, Mg2+, and O2- oxidation states of rudiments in the nanocomposite. Biologically, the CuO/MgO nanocomposite exhibits potential antibacterial activity against S. epidermidis and E. coli, with inhibition zones of 27.4 +/- 0.15 mm and 25.2 +/- 0.1 mm, respectively, and shows enhanced antioxidant activity with IC50 values of 140.72 +/- 0.6 mu g/mL. Furthermore, it demonstrates stronger inhibition of alpha-amylase and alpha-glucosidase enzymes, 79.8% and 86.1%, respectively, compared to CuO nanoparticles. Overall, this study confirms that the CuO/MgO nanocomposite, synthesized via a green approach, exhibits enhanced structural, optical, and biological properties, making it a promising candidate for biomedical applications targeting oxidative stress-related disorders.info:eu-repo/semantics/openAccessBiogenic synthesisCuO/MgO nanocompositeAntibacterialAntioxidantAntidiabeticReviewhttps://doi.org/10.1016/j.ccr.2026.217637