DNA对Ru(bpy)_2(dppx)~(2+)-SDS体系共振光散射的猝灭作用及其应用

研究了Ru(bpy)2(dppx)2+-SDS-DNA(bpy=2,2′-联吡啶,dppx=7,8-二甲基-吡啶并3,2-a:2′,3′-c]吩嗪)体系的共振光散射光谱。结果表明,在阴离子表面活性剂十二烷基硫酸钠(SDS)预胶束聚集体存在下,Ru(bpy)2(dppx)2+-SDS体系具有很强的共振光散射,DNA的加入使其共振散射光猝灭。探讨了反应机理。基于DNA对Ru(bpy)2(dppx)2+-SDS体系共振光散射的猝灭作用,建立了共振光散射法测定DNA的新方法。在最佳实验条件下,体系在393nm处的共振光散射猝灭程度与DNA的浓度呈线性关系,线性范围为0.01～1.2mg/L,检出限为1.5μg/L。

Quenching Effect of DNA on Resonance Light Scattering of Ru(bpy)2 (dppx)2+-SDS System and Its Application

The resonance light scattering（RLS） spectra of Ru(bpy)₂(dppx)²⁺-SDS-DNA(bpy=2,2'-bipyridine; dppx=7,8-dimethyl-dipyrido3,2-a:2',3'-c]phenazine) system was studied. The results show that the solution of Ru(bpy)₂(dppx)²⁺-SDS exhibits a high RLS signal in the presence of the premicellar aggregation of an anionic surfactant, sodium dodecyl sulphate(SDS), and adding DNA in the solution of Ru(bpy)₂(dppx)²⁺-SDS results in the quenching of the RLS. The mechanism of the reaction was explored. Based on the quenching effect of DNA on the RLS of Ru(bpy)₂(dppx)²⁺-SDS system, a novel RLS method for the determination of DNA was proposed. Under optimal conditions, the quenched intensity of RLS at 393 nm is proportional to the concentration of DNA. The linear range of the determination is 0.01~1.2 mg/L. The detection limit is 1.5 μg/L. This method was successful applied to the determination of DNA in synthetic and real samples.