Green Synthesis of Gold Nanoparticles Using Longan Polysaccharide and their Reduction of 4-nitrophenol and Biological Applications

The green synthesis of gold nanoparticles (Au NPs) for catalytic and biological applications has been drawing great attention. To compare with plant extracts, the polysaccharides may be good reducing and stabilizing agents. In this work, we describe the preparation of longan polysaccharide stabilized gold nanoparticles (Au n -LP NPs) by reduction of gold ions using a green synthetic method. The formation of gold nanoparticles (Au NPs) was confirmed by UV-Vis spectra. TEM showed that Au NPs had a small size (7.8–15.6[Formula: see text]nm) and were highly dispersed without any aggregation. XPS confirmed that the surface elemental composition of Au n -LP NPs was C, O, and Au. DLS demonstrated that Au n -LP NPs had good stability and negative zeta potential. In addition, Au n -LP NPs had high catalytic activity for the reduction of 4-nitrophenol. More importantly, Au n -LP NPs had ignorable cytotoxicity towards HeLa cells and showed good antioxidant activity. Taken together, the results indicated that longan polysaccharide can be used as reducing agents and stabilizers for the preparation of metallic nanoparticles, and the product had wide applications.