Structural and optical characteristics of green-synthesized ZnO/SrO nanocomposites using pomegranate peel extract and their biological activity

Nanotechnology enables the development of multifunctional nanomaterials with strong therapeutic potential. In this study, ZnO/SrO nanocomposites were synthesized via a green one-pot method using Argo waste pomegranate peel extract as a biogenic reducing and stabilizing agent. The nanocomposites were characterized in terms of optical, structural, size and shape by using various techniques. UV-Vis analysis showed a sharp absorption peak at 347 nm corresponding to a bandgap energy of 3.57 eV. FTIR confirmed functional groups involved in reduction and stabilization, while XRD revealed a crystalline structure. SEM images showed spherical particles with an average size of 98 ± 12 nm, and EDX confirmed the presence of Zn, O, and Sr. The zeta potential (-21.99 mV) and hydrodynamic diameter (229.8 nm) indicated strong colloidal stability. XPS spectra confirmed oxidation states of Zn 2p (1044.2 and 1021.1 eV), O 1 s (530.5 eV), and Sr 3d (139.4, 135.1, 133.4 eV). The nanocomposites showed potent antimicrobial activity against Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, Acinetobacter baumannii, and Candida albicans at 100 µg/mL. Cytotoxicity assays on cancer cells demonstrated an IC 50 of 70 µg/mL with apoptosis, mitochondrial membrane disruption, and ROS-mediated cell death. Overall, green-synthesized ZnO/SrO nanocomposites exhibit strong antimicrobial and anticancer potential.