钕(Ⅲ)-桑色素配合物与DNA相互作用的电化学与荧光光谱研究

Studies on the Interaction of Nd(Ⅲ)-Morin Complex with DNA by Electrochemical and Fluorimetric Methods

采用电化学和荧光光谱法对Nd(Ⅲ)-桑色素配合物与DNA的相互作用进行了研究。实验发现在pH为6.0的Tris-HCl缓冲溶液中,加入溴化十六烷基三甲铵(CTMAB)微乳液,Nd(Ⅲ)能与桑色素形成配合物并在-1.55 V(vsSCE)处产生1个灵敏的极谱波。Nd(Ⅲ)-桑色素配合物与DNA以嵌入方式生成一种非电活性超分子复合物Nd(Ⅲ)-桑色素-DNA,导致Nd(Ⅲ)-桑色素的峰电流降低,峰电流在一定范围内与DNA质量浓度呈线性关系,线性范围为1～15 mg/L,检出限为0.08 mg/L。在pH为6.0的Tris-HCl缓冲溶液中,体系的荧光强度最强,最大激发波长为392 nm,最大发射波长为535 nm。配合物荧光强度在DNA存在时增强,并与DNA的质量浓度在1～10 mg/L范围内呈线性关系,检出限为0.10mg/L,可用于DNA的测定。

The interaction of Nd （ Ⅲ ） - morin and DNA was studied by using single-weep polarography and fluorimetric methods. In pH 6.0 Tris - HCl solution, Nd （Ⅲ ） - morin complex could react with DNA to form an electrochemically non-active supermolecular complex of Nd （ Ⅲ ） - morin - DNA with the intercalation mode in the presence of hexadecyltrimethylammonium bromide （CTMAB） mi- croemulsion, which resulted in the decrease of the peak current of Nd（ Ⅲ） - morin at the potential of - 1.55 V（vs SCE）. The decrease of the peak current was proportional to DNA concentration from 1 mg/L to 15 mg/L with the detection limit of 0.08 mg/L. The fluorescence spectra of the system indicated that Nd（ Ⅲ ） - morin complex showed an maximum fluorescence peak at 535 nm and excitation wavelength at 392 nm. The adding of DNA would result in an enhancement of fluorescence intensity, and the increased fluorescence intensity was proportional to DNA concentration in the range of 1 - 10 mg/L with the detection limit of 0. 10 mg/L. The methods were further applied in the determination of DNA in synthetic samples with satisfactory results.