Selenium Nanoparticles Act as Hydrogen Peroxide Scavengers in a Simulated Biological Environment

Abstract The antioxidant properties of Se nanoparticles (SeNPs) have been frequently observed in biological systems. Reduced levels of hydrogen peroxide have been reported, but it remains unclear whether this effect is due to the increased activity of antioxidant enzymes caused by SeNPs or may be the result of their direct involvement in the reduction process. This work demonstrates the ability of SeNPs to reduce H 2 O 2 with concomitant oxidation of elemental Se to Se(VI) at physiological pH and in the presence of the major serum protein. SeNPs (96 ± 8 nm) were obtained from sodium selenite by addition of cysteine and bovine serum albumin. In a quantitative approach nanoparticles were added to the solution of hydrogen peroxide (5:1 molar excess of H 2 O 2 ) or to a solution where peroxide was continuously generated in the glucose–glucose oxidase system. During the reaction time of 60 min, oxidatively dissolved selenium and H 2 O 2 were determined by hydride generation‐microwave plasma‐atomic emission spectrometry and by UV–vis spectrophotometric assay, respectively. The results obtained indicate the conversion of SeNPs to Se(VI) in both systems. Within one hour, 5.9% of initial H 2 O 2 concentration was removed and when peroxide was enzymatically generated from glucose, its expected content was decreased by 17.2%.