DNA介导复合膜中[Ru(bpy)_3]^(2+)与Cu(Ⅱ)间光诱导电子转移  

Photoinduced Electron Ttransfer between [Ru(bpy)_3]^(2+) and Copper (Ⅱ) Ion in Composite Films Mediated by DNA

作　　者：江臻燊[1] 陈敏健[1] 李红[1] 

机构地区：[1]华南师范大学化学与环境学院,广东广州510006

出　　处：《光谱学与光谱分析》2013年第9期2332-2337,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(21271075);广东省自然科学基金项目(10351063101000001)资助

摘　　要：由于DNA与[Ru(bpy)3]2+(bpy=2,2′-联吡啶)及Cu2+间的静电作用,用自铸膜法在铟锡氧化物(ITO)上制备了橙红色[Ru(bpy)3]2+-DNA-Cu2+复合膜,并应用稳态和暂态荧光光谱、紫外可见光谱、荧光显微镜和扫描电镜对复合膜进行了表征和DNA介导的光诱导电子转移(PET)研究。结果表明,[Ru(bpy)3]2+-DNA-Cu2+复合膜(摩尔比为10∶20∶1)呈现了明显的吸收特征峰(450nm)和发射峰(λem=595nm),发光呈单指数衰减,发光寿命为188.6ns,Cu2+通过DNA介导PET机制猝灭[Ru(bpy)3]2+发光,猝灭常数为6.94×103L·mol-1,猝灭速率常数为3.80×1010 L·mol-1·s-1;复合膜中Cu2+摩尔比(10倍)的增大使发射峰蓝移了11nm,吸收和发射强度衰减至消失,Cu2+通过静态猝灭机制削弱[Ru(bpy)3]2+发光。此外,对比于溶液和复合膜中Cu2+对[Ru(bpy)2(tatp)]2+-DNA(tatp=1,4,8,9-四氮三苯)的发光调控,Cu2+仅能因静电作用猝灭复合膜中[Ru(bpy)3]2+的发光。An orange-red[Ru（bpy）3]^2＋-DNA-Cu^2＋composite film（bpy = 2,2′-bipyridine）was fabricated on an indium-tin（ITO）surface based on electrostatic interactions among[Ru（bpy）3]^2＋,DNA and Cu^2＋ by using self-standing cast methods.The photoinduced electron transfer（PET）properties of the resultant composite film mediated by DNA were studied by means of steady-state and time-resolved fluorescence spectroscopy,UV-visible absorption spectroscopy,fluorescence microscopic imaging and scan electron microscopy.The[Ru（bpy）3]^2＋-DNA-Cu^2＋composite film with molar ratio of 10∶20∶1shows an obvious absorption band（450nm）and an intense emission peak（λem=595nm）,whose emission exhibits a single-exponential decay with τ=188.6ns and is quenched by Cu^2＋via DNA-mediated PET mechanism,indicating that the quenching constant is 6.94×103 L.mol-1 and quenching rate constant is 3.80×10^10 L.mol^-1.s^-1.The increasing molar ratio of Cu^2＋in composite films（10fold）leads to an 11nm blue-shift of the emission peak,which is dramatically weakened by Cu^2＋viaa static quenching mechanism.In addition,compared with the emission quenching of DNA-[Ru（bpy）2（tatp）]^2＋（tatp=1,4,8,9-tetra-aza-triphenylene） tuned by Cu^2＋,which is present either in solutions or in composite films,Cu^2＋only quenches the emission of[Ru（bpy）3]^2＋ bound to DNAviaan electrostatic interaction mode in composite films.

关 键 词：多吡啶钌(Ⅱ)配合物 DNA 铜(Ⅱ)离子 复合膜 发光猝灭 光诱导电子转移 

分 类 号：O657.3[理学—分析化学]