title: Preparation of a DNA-bound [Ru(bpy)₂(mbpibH2)]²+ film and its two-mode luminescence tuning by copper(II) ions and EDTA.
abstract: An imidazophenanthroline-containing ruthenium(II) complex [Ru(bpy)(2)(mbpibH2)](2+) (bpy=2,2'-bipyridine, mbpibH2=1,3-bis([1,10]phenanthroline[5,6-d]imidazol-2-yl)benzene) can bind DNA through groove-binding and/or non-classical intercalation modes, revealed by spectrophotometric methods, viscosity measurements and variable ionic strength experiments. On the basis of binding interactions between cationic [Ru(bpy)(2)(mbpibH2)](2+) and anionic DNA at a molar ratio of 1:1, a yellow transparent cast film has been assembled on an indium-tin oxide (ITO) surface using a solution-based self-standing method. The prepared DNA-[Ru(bpy)(2)(mbpibH2)](2+) film shows a bi-exponential luminescence decay with τ(1)=62.1 ns (8.0%) and τ(2)=594.5 ns (92.0%), whose lifetimes become much shorter than those of DNA-bound [Ru(bpy)(2)(mbpibH2)](2+) in buffer solutions. The Ru(II) complex with a free bi-dentate coordination site in the DNA cast film shows tunable luminescence, quenched dynamically by Cu(2+) and restored by using EDTA to eliminate two modes of Cu(2+)-binding. The results from this study provide a significant foundation for better understanding the fabrication and modulation of a DNA-based solid luminescence device using the Ru(II) complexes as DNA-concentrating and signal-sensing agents.
authors: Key Lab of Technology on Electrochemical Energy Storage and Power Generation in Guangdong Universities, School of Chemistry and Environment, South China Normal University, Guangzhou 510006, PR China.
authors: Gui-Lian
authors: GL
authors: Gan
authors: Hui
authors: H
authors: Chao
authors: Shi-Bo
authors: SB
authors: Ji
authors: Lin-Lin
authors: LL
authors: Chen
authors: Hong
authors: H
authors: Li
mesh_terms: D015082:2,2'-Dipyridyl / Q000031:analogs & derivatives* / Q000737:chemistry; D000042:Absorption; D000818:Animals; D002021:Buffers; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D004492:Edetic Acid / Q000737:chemistry*; D004583:Electrons; D049449:Luminescence; D008297:Male; D009942:Organometallic Compounds / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D002021:Buffers; D009942:Organometallic Compounds; D012996:Solutions; D017971:Tin Compounds; C103599:bis(bipyridyl)ruthenium(II); D015082:2,2'-Dipyridyl; C109984:indium tin oxide; D003300:Copper; D004247:DNA; D004492:Edetic Acid