Nanostructure effect on quenching and dequenching of quantum emitters on surface plasmon-coupled interface: A comparative analysis using gold nanospheres and nanostars

Surface plasmon-coupled emission (SPCE) has emerged as a potential nanophotonic technology to understand several physicochemical interactions of nanostructured materials and biomolecules. Although a variety of templates: low-dimensional carbon, intermetallics and nano-biocomposites have been explored with silver nanoparticles, these investigations have been restricted to silver metal as primary plasmonic material. Predominant quenching of quantum emitters by gold nanospheres has prevented its study in surface plasmon-coupled emission until now. We demonstrate the robustness of gold nanostars to simultaneously obtain template-free dequenched, enhanced (100-fold), highly polarized and directional emission in SPCE. Nanostructure dependent plasmonic property exhibited by sharp nanotips for optical energy confinement is demonstrated.