Synthesis of selenium nanowires morphologically directed by Sinorhizobial oligosaccharides.

Shinorhizobial cyclosophoraose (cyclic beta-(1-->2)-glucan) or succinoglycan monomer (SGM 2), which has one acetyl, pyruvyl, and succinyl group, functions as a morphology-directing agent for the synthesis of pure trigonal selenium nanowires by using ascorbic acid (vitamin C) as the reducing agent. The synthesis was achieved in water at room temperature. Under these experimental conditions, the diameters of the as-prepared Se nanowires were varied in the range of 34-120 nm by cyclosophoraose and of 33-66 nm by SGM 2, in which the nanowires were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Through this study, we propose that Shinorhizobial cyclic and linear oligosaccharides have morphologically directing functions for the synthesis of single-crystalline selenium nanowires by green chemical methods.