ABSTRACT ZnO nanoparticles were synthesized by reverse micelle (RM) and sonochemical (SM) methods using a precursor of zinc nitrate salt. The physicochemical properties of the synthesized powders were thoroughly investigated for crystal structure, size, morphology, and chemical composition. Antibacterial activity and cytocompatibility of the nanoparticles were also determined for their applicability. X‐ray diffraction (XRD) indicated the presence of hexagonal wurtzite phase. The SM method yielded spherical ZnO nanoparticles between 12 and 16 nm, whereas RM method yielded narrow size distribution ranging from 5 to 7 nm due to RM acting as a particle size‐controlling nano‐reactor. These nanoparticles self‐assembled to form nanoflowers as revealed by FESEM micrographs. All ZnO nanoparticles effectively inhibited Staphylococcus aureus growth at the fastest rate, indicating strong antibacterial efficacy. However, RM‐synthesized Zn showed antibacterial activity at relatively lower concentration in comparison to SM‐method. Cytotoxicity assay using 3T3 fibroblast was performed, in which the RM‐synthesized ZnO shows good cytocompatibility (75%) for lower concentrations up to 40 µg/mL after 72 h, while SM‐produced ZnO maintained 88% cell viability even at 100 µg/mL. These results demonstrate that SM method is a simple, cost‐effective approach for bulk production of ZnO nanoparticles, as an antibacterial agent for biomedical applications without compromising cell viability characteristic.
Sonali et al. (Fri,) studied this question.