Studies on interaction of an intramolecular charge transfer fluorescence probe: 4′-Dimethylamino-2,5-dihydroxychalcone with DNA

The interaction of a new intramolecular charge transfer probe, namely 4′-dimethylamino-2,5-dihydroxychalcone (DMADHC), with calf thymus DNA has been studied. Compared to the spectral characteristics of the free form in aqueous solution, the fluorescence of DMADHC enhanced dramatically accompanying a blueshift of the emission maxima in the presence of DNA. The absorption and fluorescence spectra, salt concentration effect, KI quenching, fluorescence polarization, and DNA denaturation experiments were given. These results give evidence that the DMADHC molecule is inserted into the base-stacking domain of the DNA double helix. The intrinsic binding constant and the binding site number were estimated. The analytical characteristics were also given.

An intramolecular charge transfer fluorescence probe binding to DNA exhibited dramatic enhancement of fluorescence intensity accompanying blueshift of the emission maximum. Experimental results give evidence that this probe is inserted into the base-stacking domain of the DNA double helix.Figure optionsDownload as PowerPoint slide