Synthesis and surface enhanced raman scattering properties of gold nanoworms

We have devised a simple seedless, high-yield protocol for the synthesis of gold nanoworms (NWs). NWs were grown simply by reducing HAuCl4 with ascorbic acid (AA) in the presence of cetyltrimethylammonium bromide (CTAB) and NaOH. The nucleation was induced by the addition of AgNO3 in the reaction medium. We have observed that an optimum range of NaOH concentration is essential for NW formation. Furthermore, we have seen that the synthesis of gold NWs is very sensitive to the supplier of the CTAB used for the synthesis. With the same recipe, CTAB from different suppliers gave different yield and lengths of NWs. The NWs show excellent potential for surface enhanced Raman spectroscopy (SERS).