Preparation and antioxidant activity of selenium nanoparticles decorated by polysaccharides from Sargassum fusiforme.

In this study, the response surface method was employed to optimize the extraction conditions of the ultrasonic-assisted extraction of Sargassum fusiforme polysaccharides (SFPS). The effects of four independent variables (hot water extraction time, ultrasonic time, ultrasonic power, and material-to-liquid ratio) on the extraction rate of SFPS were tested. In addition, the SFPS functionalized nanoselenium (SFPS-SeNPs) was prepared by chemical reduction method, whose characterization and in vitro antioxidant activity were investigated. The results showed that the yield of the crude SFPS was 25.8% at the optimal conditions of material-to-liquid ratio 1:50 (w/v), ultrasonic power 200 W, ultrasonic time 15 min, and water bath time 130 min. A series of characterization experiments showed that the SFPS-SeNPs performed higher dispersion and stability than naked SeNPs. Furthermore, the in vitro antioxidant activity assay indicated that SFPS functioned as a modifier improved the free radical scavenging activity of SeNPs significantly. In conclusion, this study provided a method to extract SFPS as a carrier for SeNPs, and SFPS-SeNPs could not only improve the stability of SeNPs, but also exerted the biological activities of SFPS. PRACTICAL APPLICATION: This research provided new ideas for the application of SFPS and the development of nanoselenium preparation carriers.