Formation of submicron scale particles of narrow size distribution from a water-soluble dendrimer with links to porphyrins and a fullerene

A water-soluble L-lysine dendrimer (6) with links to porphyrins and a fullerene was synthesized, in which the dendrimer Surface was modified with carboxylate groups. The aqueous Solution of 6 showed the Soret band characteristic of the aggregated porphyrins in the UV-vis spectra; however, this aggregate was dissociated by the addition of 2-hydroxypropyl-beta-cyclodextrin (10 wt % in H2O). TEM and AFM showed the formation of submicron-scale particles of 6. TEM showed the spherical particles of 6 with almost uniform size (100-110 nm) in the presence of the cyclodextrin. AFM showed the oval particles of 6 ill the absence of the cyclodextrin. DLS measurement indicated that cyclodextrin dissociated the aggregated structure of 6 in H2O. Thus, a large number of porphyrins and fullerenes were Successfully accumulated with a narrow size distribution via the particle formation of the amphiphilic dendrimer.