Synthesis, characterization and antimicrobial activity of monodisperse selenium nanoparticles on streptococcus mutans

Marzieh Khayam nekuii,1 Tahereh tohidi moghadam,2,* Bita bakhshi,3

1. Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
2. Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
3. Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran



Over the past few decades, excessive and inappropriate use of antibiotics has led to the emergence of drug-resistant bacteria. the use of nanotechnology in biology has provided many opportunities in many areas, including tissue engineering, drug delivery, diagnosis, imaging and the fight against bacterial infections. with the need for new antimicrobial agents, nanoparticles have been proposed for the treatment of infections because they use different mechanisms to kill bacteria than conventional antibiotics. selenium nanoparticles (senps) ¬have recently drawn big attention due to its excellent antimicrobial activity and less toxic compared with many metal-based nanomaterials. the objective of this investigation was to analyze the antimicrobial activity of senps against common biofilm-forming dental plaque gram-positive bacterium streptococcus mutans wich is the main etiological agent of dental caries worldwide.


senps were synthesized by a facile reduction method. ascorbic acid was used as a reduction agent and a common emulsifier polysorbate 20 as a surfactant was added to control the size of nanoparticles. the quality and size of the nanoparticles was characterized by scanning electron microscopy (sem), dynamic light scattering (dls), and ultraviolet–visible (uv–vis) absorption spectroscopy. concentration of selenium nanoparticles was assessed by icp analysis. antimicrobial potential of polysorbate 20 stabilized senps was tested in vitro using streptococcus mutans by disk diffusion method.


Analysis of the purified nanoparticles indicated that stable senps have been synthesized with average diameter of 33 nm, with a narrow size distribution (pdi = 0.05) and 1300 ppm concentration. the colloidal senps showed antimicrobial activity with inhibition zone of 3.5mm against s. mutans


Results of this investigation encourage the possibility of synthesis of stable colloids of senps with narrow size distribution which can be fulfilled through chemical reduction method, showing good antimicrobial activity against s. mutans . this paves the way to utilize senps as potential candidates for developing a new generation of antibacterial agent for future biomedical applications.


Selenium nanoparticles, polysorbate 20, antimicrobial activity