Siloxane surfactant induced self-assembly of gold nanoparticles and their application to SERS

A siloxane surfactant was used for the mild synthesis and simultaneous 1D assembly of gold nanoparticles. The length of the gold nanochains could be tuned by facile adjustment of the surfactant concentration. The multiple interactions between the siloxane surfactant and gold nanoparticles made the non-uniform spatial distribution of stabilizers at the nanoparticle surfaces and then led to the 1D assembly. Transmission electron microscopy (TEM) and UV-vis spectroscopy have been employed for characterizing the nanochains. The effect of ionic strength in the spontaneous linear assembly of gold nanoparticles was investigated to further elucidate the assembly of mechanism. These gold nanochains were shown to yield a large SERS enhancement for Rhodamine 6G.