Synthesis of indium–silver bimetallic nanocomposites for surface-enhanced Raman scattering

We report on the synthesis of indium–silver bimetallic nanocomposites by chemical reduction method under atmospheric condition and their activity for surface-enhanced Raman scattering (SERS). It is found that the indium–silver bimetallic nanocomposites have better SERS activity with larger enhancement factors (EF) than pure silver nanoparticles with similar size. The SERS EF can reach 107 for 4-mercaptobenzoic acid and 109 for crystal violet and rhodamine 6G adsorbed on the nanocomposites and the detection limits can be at least down to 10−7 and 10−10 M, respectively. The results demonstrate that the indium–silver bimetallic nanocomposites are promising as SERS substrate for a myriad of chemical and biological sensing applications.