Preparation and Antioxidant Capacity of Element Selenium Nanoparticles Sol–Gel Compounds

This paper reported the preparation and antioxidant capacities of element selenium nanoparticles (nanoSe⁰-ascorbic acid (Vc) sol and nanSe⁰/Vc/selenocystine (SeCys) sol–gel compounds. NanoSe⁰-Vc sol was prepared by reduction of selenious dioxide (SeO₂ with Vc. In the nanoSe⁰-Vc sol, highly concentrated Vc was also used as a modifier to modulate the diameter of Se⁰ nanoparticles in the liquid phase. Then excellent nanoSe⁰ sol–gel compounds were obtained by adding SeCys into the nanoSe⁰-Vc sol. The structure of the nanoSe⁰/Vc/SeCys sol–gel compounds was defined, which was constructed via C–Se, Se–H and O=C–Se valences and by interaction between SeCys and Vc via peptide bonds, esterification and dehydration. The antioxidant capacities of the nanoSe⁰-Vc sol and the nanoSe⁰/Vc/SeCys sol–gel compounds were estimated by oxygen radical absorption capacity (ORAC) assay. The nanoSe⁰/Vc/SeCys sol–gel compounds possessed a strong antioxidant capacity due to forming the perfect three-dimensional (3D) frameworks structure. The results suggested that the nanoSe⁰-Vc sol and the nanoSe⁰/Vc/SeCys sol–gel compounds might be potential medicine, especially antioxidant.