Hydrotropic solubilization of gold nanoparticles functionalized with proto-alkylthioporphyrazines

ABSTRACT Hydrotropic anchoring of a prototype porphyrazine bearing eight ethylthio chains as peripheral substituents was shown to take place on gold nanoparticles (GNPs) by UV−vis, dynamic light scattering (DLS), Raman, resonance Raman (RR), and surface enhanced resonance Raman spectroscopy (SERRS) experiments. Density functional theory (DFT) calculations were used as a valuable help to make the hypothesis that ligation to the gold surface occurred through the concurrent contribution of the peripheral sulfur atoms and the π system of the macrocycle. The so functionalized GNPs proved to be stable in water solution for long time, thus providing a suitable chemical and structural basis to build up hierarchical structures with possible applications in technological and biomedical fields.