Hydrophobic Au nanocrystal assemblies (both ordered and amorphous) were dispersed in aqueous solution via the assistance of lipid vesicles. The intertwine between vesicles and Au assemblies was made possible through a careful selection of the length of alkyl chains on Au nanocrystals. Extinction spectra of Au assemblies showed two peaks that were assigned to a scattering mode that red-shifted with increasing the assembly size and an absorption mode associated with localized surface plasmon, that was independent of their size. This plasmon fingerprint could be used as a probe for investigating the optical properties of such assemblies. Our water-soluble assemblies enable exploring a variety of potential applications including solar energy and biomedicine.
Source : Water-Dispersed Hydrophobic Au Nanocrystal Assemblies with a Plasmon Fingerprint. Yang, C.Deeb, J.L Pelouard, N. Felidj and M.P. Pileni ACS Nano, 2017,11, 7797−7806.