eng Science and Education Publishing American Journal of Nanomaterials 2372-3122 2025-10-13 13 1 7 11 10.12691/ajn-13-1-2 AJN20251312 article Rebecca ¨¢lvarez Arceo 1 Esteban Hern¨¢ndez Guevara 1 Judith Lerma Sevilla 1 Adolfo Neftal¨ª Garc¨ªa-Barr¨®n 1 Fernanda Araiza-Verduzco maria.araiza18@uabc.edu.mx 1 Faculty of Dentistry, Autonomous University of Baja California (UABC), Tijuana, Mexico Green nanotechnology provides sustainable alternatives for synthesizing functional materials with biomedical potential. This study reports the green synthesis of titanium dioxide (TiO?) and silver (Ag) nanoparticles using aqueous extracts of Rosmarinus officinalis (rosemary, RO) and Syzygium aromaticum (clove, CL) as natural reducing and stabilizing agents. UV¨CVis spectroscopy confirmed nanoparticle formation, with TiO? showing its characteristic absorption band and Ag/TiO? composites exhibiting a bathochromic shift indicative of Ag¨CTiO? interactions. Scanning electron microscopy revealed predominantly spherical nanoparticles, averaging ~165 nm for TiO? and ~96 nm for Ag deposits, while energy-dispersive spectroscopy verified elemental composition. Antibacterial assays demonstrated markedly enhanced activity of Ag/TiO? nanocomposites compared to TiO? alone, with effective inhibition against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, although lower efficacy was observed against Enterococcus faecalis. Interestingly, TiO? nanoparticles synthesized with CL extracts exhibited selective antibacterial effects, while RO-based coatings appeared to reduce antimicrobial performance. The combined bioactivity of plant-derived phytochemicals and Ag/TiO? nanostructures highlights a synergistic approach for developing biocompatible, eco-friendly antibacterial agents. These results suggest that RO- and CL-mediated Ag/TiO? nanocomposites hold promise as adjunctive materials in restorative dentistry, particularly for pulpotomy applications where antibacterial efficacy is essential. https://pubs.sciepub.com/ajn/13/1/2/ajn-13-1-2.pdf Dioxide titanium nanoparticles silver nanoparticles antibacterial properties