Abstract
Aim: The aim of the present study was to prepare selenium nanoparticles using coriander oleoresin and evaluate its antimicrobial activity .
Materials and Method: In a conical flask, 99 mL of distilled water was taken and added with 0.5ml of Coriander oleoresin extract. 0.519 g of Sodium selenite was added to the extract and kept in the orbital shaker for nanoparticle synthesis and the colour change was noted. The absorbance of the reaction mixture was noted using UV- Visible spectroscopy periodically and the final product was centrifuged for 10 minutes and selenium nanoparticles were collected. The prepared coriander oleoresin mediated Selenium Nanoparticles were evaluated for its antibacterial activity against Streptococcus mutans and Lactobacillus sp and antifungal activity against Candida albicans by standard procedure.
Results and Discussion: In this, In Vitro study, visual observation of the colour change showed the formation of selenium Nanoparticles and was further confirmed by UV- Visible spectrophotometer with a peak at 360 nm. The different concentration of coriander oleoresin mediated selenium nanoparticles showed dose dependent antimicrobial activity. against the tested microorganism. Streptococcus mutans, Lactobacillus sp and Candida albicans. It was showing better effect on S.mutans with a maximum zone of inhibition 25mm at 150 µL and against C.albicans it showed a zone of inhibition of 30mm.
Conclusion:The present study showed that coriander oleoresin mediated selenium nanoparticles proven to be a better choice against oral bacteria Streptococcus mutans, and fungal species Candida albicans .Hence, this green synthesised coriander oleoresin mediated selenium nanoparticle may be utilized for the control of such infection.

Key words: Coriander oleoresin, Selenium nanoparticle, Streptococcus mutans, Candida albicans, Lactobacillus sp.