Structuralization of metal nanoparticles by photoinduced aggregation

Aggregate of metal nanoparticles is an ideal material for sensing devices such as SERS. Controlled production of aggregates with desired parameters is very important to optimize its usage. We proposed a method to produce aggregates of metal nanoparticles through structuralization of metal nanoparticles by using photoinduced aggregation with optical trapping technique. In this study, we demonstrate that the gold nanoparticles can be gathered, aggregated and deposited on the surface of silicon wafer through optical trapping and photoinduced aggregation. 532nm green laser which is near-resonant to the plasmon resonance wavelength of the gold nanoparticles, is found to cause more aggressive reaction than the off-resonant 1064nm YAG laser. The growth of the aggregates formed is also found to be influenced by the laser exposure time.