CHED 1176 |
| It is known that ruthenium complexes can act as fluorescent light “switches” for use in the detection and interrogation of DNA. The following: [Ru(bpy)2dppz]2+, [Ru(bpy)2dppx]2+, [Ru(phen)2dppz]2+ and [Ru(phen)2dppx]2+ where bpy = 2,2'- bipyridine, phen = 1,10-phenanthroline, dppz = dipyrido [3,2-a:2',3'-c]phenazine, dppx = 7,8 dimethyl-dipyrido[3,2-a:2',3'-c]phenazine are known to be efficiently quenched in aqueous solutions. This interaction leads to efficient deactivation of the lowest lying triplet MLCT excited state via non-radiative pathways and the resulting solutions show virtually no emission. When DNA is added to these solutions, significant increases in the quantum yields of emission are observed. This effect has been ascribed to intercalation of the pendant dppx or dppz ligands into hydrophobic cavities present in double helix DNA. The intensity of the resulting fluorescence depends upon the number of mismatches present in a sequence of DNA. A DNA sequence containing no base pair mismatches demonstrates a benchmark fluorescent intensity. When a base pair mismatch is introduced into the sequence, the florescence intensity is decreased compared to the fluorescence of the sequence containing no mismatches. The decrease in fluorescence intensity continues as the number of mismatches in a DNA sequence increases. |
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Undergraduate Research Poster Session: Inorganic Chemistry
2:00 PM-4:00 PM, Monday, March 26, 2007 Hyatt Regency Chicago -- Riverside Center, Poster
Division of Chemical Education |