Click chemistry binding of colloidal quantum dots and gold nanoparticles revealed by combined confocal DLS and FCS

Click chemistry reactions were employed to synthesize hybrid systems consisting in CdSe-ZnS quantum dots (QDs) and gold nanoparticles (AuNPs). These colloidal systems were characterized by an experimental approach of combined confocal dynamic light scattering and fluorescence correlation spectroscopy which we developed to independently study the hydrodynamic properties of the QDs and those of the AuNPs. We demonstrate that this method allows to unambiguously reveal the particles binding, even in cases where this issue cannot be ascertained by common experimental approaches. Furthermore, we determined the nature of the formed hybrid systems using a hydrodynamic bead model approach, and characterized the efficiency of the reaction process. None of these results are accessible through other characterization methods and they pave the way for a more quantitative understanding of the physicochemical properties of such hybrid systems.