Application of green silver nanoparticles synthesized from the red seaweeds Halymenia porphyriformis and Solieria robusta against oral pathogenic bacteria by using microscopic technique.

Aqueous extracts of two red seaweeds and were used to synthesize green silver nanoparticles. These biogenic nanoparticles were tested against four strains of oral pathogenic bacteria which cause tooth decay or cavities. (MT416445), (MT416448), (MT416447) and (MT416446) were used. Characterization of AgNPs was done by UV-Visible spectroscopy, SEM, XRD and FTIR. XRD analysis revealed the crystalline nature of the particles. The size analysis by XRD of the green AgNPs by indicated it had smaller particles, 15.23 nm, when compared to AgNPs by (17 nm). Both green synthesized silver nanoparticles showed moderate antibacterial activity against all strains of bacteria, except . Both particles showed their maximum zone of inhibition against at a lower concentration of 50 and 100 μg. However, it was concluded that silver nanoparticles of are more effective than that of due to their smaller size.