We report on a simple, universal and large scale self-assembly method for generation of spherical superclusters from nanoscopic building blocks. The fundamentals of this approach relies on the ultra-high pre-concentration of nanoparticles (NP) followed by either using emulsification strategies or alternatively multiphase microfluidic microdroplets. In both cases drying of the NP droplets yield highly spherical self-assembled superclusters with unique optical properties. We demonstrate that the behaviour of these spheres can be controlled by surface functionalization before and after the self-assembly process. These structures show unique plasmonic collective response both on the surface and within the supercluster in the visible and infrared regions. Furthermore, we demonstrate that these strong, tunable optical modes can be used towards ultra-sensitive, reproducible, surface-enhanced spectroscopies.