Green synthesis, characterization and optimization of silver nanoparticles from Carica papaya using Box Behnken design and its activity against dental caries causing Streptococcus sp

In current scenario, Oral diseases are the most prevalent and challenging diseases globally and it causes serious health and economic burdens for those who are affected. Carica papaya is used to treat oral diseases in Ayurvedic medicines from very long time. In current study aqueous leaf extract of C. papaya utilize to green synthesize silver nanoparticles for oral pathogen treatment. Green synthesized silver nanoparticles from C. papaya characterized using UV–Visible, FTIR, XRD and SEM analysis. Green synthesis of silver nanoparticles from C. papaya optimized by utilizing Box–Behnken based response surface methodology software. Characterization of green synthesized silver nanoparticles from C. papaya reveals that has maximal absorbance at 510 nm shown strong vibrational band at 3490 cm⁻¹ in IR analysis indicate silver nanoparticle formation. SEM analysis reveals 30–55 nm sized spherical shaped nanoparticles which was further affirmed by XRD analysis. Further green synthesized silver nanoparticles synthesized from C. papaya leaf extract shown anti-microbial activity against dental caries causing microorganism with zone of inhibition values 10, 14, 15 mm diameter respectively against S. mutans (ATCC25175), S. gordonii (ATCC10558), S. anginosus (ATCC33397) dental caries pathogen at 10 µg nanoparticle concentration. The functional groups of bioactive compounds from C. papaya responsible for effective reduction of silver ions and its inhibitory activity against tooth decay causing bacteria were assayed in this current research study. The current study proven that the green synthesized silver nanoparticles from C. papaya leaf extract possess significant applications in dental applications and we recommend this silver nanoparticle found suitable applications in biomaterial applications in dental industry.