Green synthesis, characterization, phytochemical analyses, and antibacterial evaluation of Ag/TiO₂ and Ag/TiO₂-chitosan nanocomposites derived from M. chamomilla

Research on green synthesis performance has gained prominence because nanotechnology needs eco-friendly sustainable approaches for various applications. This work used Matricaria chamomilla extract as a capping and reducing agent for novel biosynthesis of novel Ag/TiO₂ and Chitosan-coated Ag/TiO₂ nanocomposites. The characterization of nanocomposites by FTIR, UV–Vis Spectroscopy, HR-TEM, SEM, zeta potential, EDX, and XRD analysis provided important information about the structural, optical, morphological elements, elemental composition, and crystallinity of nanocomposites. An anthrone assay determined the carbohydrate content of the plant extract along with the nanocomposites to study carbohydrate contribution during nanoparticle development as well as the improved contents by the incorporation of chitosan into the nanocomposite. The combination of chitosan with Ag/TiO₂ NC enhanced antioxidant behavior until an IC₅₀ value reached 0.769 mg/mL, in which at this point the activity exceeded that of Ag/TiO₂ NC. The antibacterial performance of Chitosan-coated Ag/TiO₂ nanocomposite surpassed Ag/TiO₂ NC since this nanocomplex provided increased inhibition against all investigated Gram-positive bacteria. The highest antibacterial zone of inhibition measured 22 ± 1.17 mm against S. aureus and 15 ± 1.60 mm against B. subtilis. The same zone of inhibition (24 ± 0.88 mm) was developed from Ag/TiO₂ NC against S. aureus while S. aureus was the most susceptible bacterial species to both nanomaterials. The incorporation of chitosan into the nanocomposite enhanced its antioxidant capabilities as well as its antibacterial properties owing to the combined effects of Chitosan-coated Ag/TiO₂ nanocomposite synergy. Thus, biological applications could benefit from green synthesized nanocomposites that work toward solving contemporary global issues.