SERRS study of the DNA binding by Ru(II) tris-(Bipyridyl) complexes bearing one carboxylic group.
Surface enhanced resonance Raman scattering (SERRS) is shown to be a satisfying method to study the interaction between DNA and ruthenium complexes [Ru(bpy)(2)(Hcmbpy)][PF(6)](2), where Hcmbpy = 4-carboxy-4'-methyl-2,2'-bipyridine. Such metallic complexes are known for their fluorescence properties. To validate this spectroscopic approach we have checked that i) at a given lambda(ex), silver colloidal SERRS spectra of Ru complexes closely resemble resonance Raman spectra in aqueous solutions, intensity excepted, and ii) the DNA fragments are not altered when they are adsorbed on the Ag nanoparticles surface. This investigation shows that the intensity of the Ru complexes SERRS spectra is reduced in the presence of DNA, in particular for the specific bands assigned to the Hcmbpy ligand. This collapse demonstrates that the Ru complexes bind DNA through the Hcmbpy moiety, and intercalation is suggested as the binding mode. The DNA binding by the enantiopure Ru complexes (Delta or Lambda) is more efficient than by the racemic complexes.
Gaudry
E
E
ITODYS, UMR CNRS 7086, Université Paris 7, Denis Diderot, 1 rue Guy de la Brosse, 75005 Paris, France.
Aubard
J
J
Amouri
H
H
Lévi
G
G
Cordier
C
C
D015082:2,2'-Dipyridyl / Q000737:chemistry*; D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry* / Q000378:metabolism; D012428:Ruthenium / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013237:Stereoisomerism
D009942:Organometallic Compounds; D015082:2,2'-Dipyridyl; D012428:Ruthenium; D004247:DNA