Equisetum ramosissimum desf-assisted green synthesis of cerium oxide nanoparticles: Characterization and antimicrobial potential against cariogenic Streptococcus mutans.

Objective(s): This study explores the biosynthesis of cerium oxide nanoparticles using aqueous extract of Equisetum ramosissimum Desf as both a reducing and stabilizing agent and evaluates its antibacterial activity against cariogenic streptococcus mutans. Materials and Methods: Cerium oxide nanoparticles were synthesized and characterized using UV-VIS, FTIR, XRD, FESEM, EDX, DLS, and Zeta potential analyses. Antibacterial activity against S. mutans was evaluated via the agar well diffusion method. Results: Optical analysis revealed an absorption peak within the 307-314 nm range, suggesting a bandgap value of 3.04-3.37 eV. FTIR analysis confirmed Ce-O stretching vibrations and bonds with phytochemicals from the E.ramosissimum Desf extract on the nanoparticle surfaces. XRD showed a cubic fluorite structure with a crystalline size of 5.99-11.74 nm. FESEM imaging depicted uniform, nearly spherical nanoparticles with estimated sizes ranging from 22 to 31 nm. The EDX spectrum indicated the presence of cerium and oxygen signals, affirming the purity of the fabricated nanoparticles. DLS results corroborated the average nanoparticle size (28.11-54.61 nm), in agreement with FESEM findings and zeta potential values (-11.4 to 29.2 mV) indicating moderate stability of nanoparticles. Antibacterial assays showed significant inhibition zones (20-32 mm) against S. mutans. Conclusion: The green-synthesized CeO2-NPs exhibit promising antimicrobial efficacy against S. mutans, suggesting their potential for dental applications. Furthermore, employing plant extract for cerium salt reduction presents a promising avenue for reducing the environmental impact associated with chemical synthesis. [ABSTRACT FROM AUTHOR]