Preparation of Gold−Tellurium Hybrid Nanomaterials for\nSurface-Enhanced Raman Spectroscopy

Abstract

We report a simple method for preparing three different SERS-active substrates. Concentrated hydrazine solution\nas the reducing agent and tellurium dioxide as the precursor were used to prepare Te nanowires (NWs). The as-prepared\nTe NWs have an average length of 547.7 ± 111.6 nm and an average width of 15.1 ± 2.7 nm. Through the reaction\nof Te NWs with sodium tetrachloroaurate in the presence of hexadecyltrimethylammonium bromide (CTAB) over\nreaction times of 10, 20, and 60 min, gold−tellurium nanodumbbells, gold−tellurium nanopeapods, and gold pearl-necklace nanomaterials (Au PNNs) were obtained, respectively. By controlling the reaction time, the distance between\nadjacent gold nanoparticles (Au NPs) in each Te nanowire was tunable, allowing us to investigate its effect on the\nSERS signals. Having shorter distances among Au NPs (greater electromagnetic fields), the Au PNNs provided a\nreproducible enhancement factor of 5.6 × 10⁹.