利福霉素类抗生素-Cu(II)-核酸体系的RRS光谱研究

在Britton-Robinson (B-R)缓冲溶液中, 利福霉素类药物与ctDNA反应的适宜的pH范围是1.9～2.1. 此类药物本身有微弱RRS峰, 它们具有相似的光谱特征, 其散射峰均在290和370 nm附近; 而ctDNA的RRS峰在310 nm处. 两者反应形成结合产物后其RRS明显增强, 并在375 nm左右出现最大散射峰, 且有不同程度的红移和散射增强, 说明两者结合成新的产物; 加入Cu2＋离子后, Cu2＋与利福霉素抗生素及DNA形成三元复合物, 此时将导致RRS进一步剧增, 而且RRS光谱增强值与DNA浓度呈正比, 因而可用于DNA测定具有较高的灵敏度, 实验对ctDNA的检出限为9.7 ng/mL (RFSV-Cu2＋- ctDNA体系). 文中研究了三元配合物反应的适宜条件和影响因素, 基于此反应发展了一种用RRS技术测定DNA的新方法.

Resonance Rayleigh Scattering Spectra of Rifamycins Antibiotics-Cu(II)-Nnucleic Acid System

In the pH 1.9～2.1 Britton-Robinson (B-R) buffer solution, rifamycin drugs such as Rifamycin SV (RFSV), Rifapentine (RFPT) and Rifampicin (RFP) could react with ct-DNA. These rifamycin drugs themselves had slight resonance Rayleigh scattering (RRS) spectral peaks and analogical spectral characteristics with RRS peaks at around 290 and 370 nm; meanwhile, ctDNA had a faint peak at 310 nm. The RRS intensity was enhanced obviously after the drugs and DNA reacting with each other, which indicated the formation of new products for the maximum peak appeared at around 375 nm with slight red shift. Then the Cu(II) ion was added into the system to form a ternary system, and the RRS intensity was enhanced significantly, when the enhanced spectral value was directly proportional to the concentration of the DNA. Thus a highly sensitive method could be obtained for determining DNA and the detection limit of the experiment reached 9.7 ng/mL for the RFSV system. In this work, the optimum reaction conditions and influencing factors were investigated and a new method for the determination of DNA has been developed by the RRS spectral technology.