A series of new water-soluble cationic pyrene-dendron derivatives, G1, G2, and G3, was successfully synthesized and characterized. These new dendrons were designed with the quaternized amino moieties at the periphery of the dendrons for DNA detection and functionalized with pyrene as a fluorescent probe. The electrostatic interactions between the plasmid DNA (pDNA) and cationic charged dendrons in an aqueous solution resulted in a change in the photophysical properties of pyrene, which could be shown in the UV-vis and fluorescence spectra. Pyrene dendrons showed a high and rapid fluorescence response upon the addition of pDNA, which was strongly dependent on the size and hydrophobicity of the dendrons. (C) 2011 Wiley Periodicals, Inc. J PolymSci Part A: Polym Chem 50: 297-305, 2012