A shrinking strategy for creating dynamic SERS hot spots on the surface of thermosensitive polymer nanospheres.

This study reports a strategy that allows one to finely tune the distance between Ag nanoparticles decorated on thermoresponsive microgels to create vast 'hot spots' for electromagnetic enhancement. The dynamic gap (i.e. the interparticle distance) can be tuned easily because the microgel template undergoes a phase transition upon changing the temperature. This change could increase the SERS intensity for three orders of magnitude.