부산대학교 도서관

We report on biosynthesis of silver nanoparticles using aqueous leaf extract of Euphorbia sanguinea and its photocatalytic degradation of Congo red dye and melanogenesis inhibition activity of mushroom tyrosine enzyme. Surface Plasmon resonance bands obtained from UV-Vis spectra were within the range 430–436 nm. FT-IR studies reveal the presence of functional groups of the plant metabolites used as stabilizing agents of nanoparticles. The shape of silver nanoparticles is spherical with size ranges about 20–28.8 nm as confirmed by SEM. XRD patterns displayed well-defined crystalline peaks corresponding to the face-centred cubic structures of metallic silver nanoparticles. The results of photocatalysis showed high photocatalytic efficiency of 86% and 90% within 5 min and 60 min, respectively at a rate of solar radiation of in the degradation of Congo red dye. The AgNPs gave dose dependent melanogenesis inhibition activity with IC50 of 71.96 µg/ml, showing non competitive mode of inhibition. Rapid formation of silver nanoparticles using 0.5 mL extract of Euphorbia sanguinea. AgNPs are spherical, monodispersed and with sizes in the range of 20–29 nm. High photocatalytic efficiency of 86% was obtained within 5 min of solar radiation of AgNPs in the degradation experiment of Congo red dye. First order kinetics with a correlation coefficient of 0.9472 and a rate of 0.0063 min−1 was established for the photocatalytic process. AgNPs showed dose dependent melanogenesis inhibition activity of IC50 71.96 µg/ml. [ABSTRACT FROM AUTHOR]