LAUSR

Selenium nanoparticles (SeNPs), which have been considered as antioxidant and potent anticancer agents, have become a focus of research. In this work, monodispersible SeNPs with two different sizes were synthesized using a facile synthetic approach. The structure, morphology, size and surface analysis of the SeNPs were characterized by transmission electron microscopy (TEM), ultraviolet-visible spectroscopy (UV-vis), Dynamic Light Scattering (DLS), and X-ray Photoelectron Spectroscopy (XPS). The direct evidence for the ˙OH scavenging activity of SeNPs was established by using a simple photometric system in vitro. When methyl violet (MV) reacted with the ˙OH, the absorbance change indicated the ˙OH level. The presence of SeNPs protected MV by competitively reacting with the ˙OH, so their ˙OH scavenging activity was directly seen through the absorbance change. The results of the Electron Spin Resonance (ESR) experiment agreed with that of the chromogenic reaction of MV. The ˙OH scavenging activity of SeNPs was also proved to be associated with the particle size.