Silver nanowires were prepared by anodic aluminum oxidation (AAO) template combined with AC electrodeposition. By the chemical reduction and controlling the concentration of gold salt, gold shell was covered onto the silver nanowires with different thickness to prepare Ag_coreAu_shell nanowires. The surface morphology was dependent on the amount of gold salt. SEM, TEM and surface enhanced Raman spectroscopy (SERS) were employed to characterize the composite nanowires. Thiophenol (TP) and p-aminothiophenol (PATP) were used as probe molecules to investigate the SERS effect of the core-shell nanowires. The quality of the gold shell was identified by comparing the differences of spectral feature of PATP absorbed onto nanowire surface. The results revealed that Ag_coreAu_shell nanowires were a potential SERS substrate and the pinhole free Ag_coreAu_shell nanowires were obtained by controlling the shell in a certain thickness range.

Key words: template, Ag nanowire, core-shell, surface enhanced Raman spectroscopy, p-aminothiophenol