A polyphenylene dendrimer-detergent complex as a highly fluorescent probe for bioassays

The synthesis of a polyphenylene dendrimer carrying three perylenemonoimide dyes as well as one biotin group is presented. Due to the hydrophobic polyphenylene scaffold, this dendrimer is insoluble in water thus preventing investigations in aqueous media. However, the use of an appropriate detergent results in the formation of well-defined supramolecular dendrimer-detergent complexes being soluble in aqueous media. The dendrimer-detergent complexes have a constant hydrodynamic radius of 7.1 nm measured by light scattering and fluorescence correlation spectroscopy and exhibit a high stability in the presence of blood serum proteins. The specific binding of the dendrimer-detergent complexes carrying a single biotin group to the protein streptavidin is demonstrated using a magnetic bead assay.