采用紫外-可见、荧光光谱等研究手段,确定了γ-环糊精-中性红包合物(γ-CD-NR)与鲱鱼精DNA之间存在嵌插和静电两种作用方式.用摩尔比法和双倒数法确定了γ-CD与NR的包合比nγ-CD∶nNR=1∶1,包合常数Kf=2.08×10^3L·mol^-1.γ-CD-NR包合物与鲱鱼精DNA的结合比nγ-CD-NR∶nDNA=4∶1,结合常数K25℃ =2.11×10^6L·mol^-1.化学热力学研究显示γ-CD-NR包合物与鲱鱼精DNA的结合为熵驱动.以吖啶橙(AO)作荧光探针,研究发现γ-CD-NR包合物和AO在与DNA作用时存在竞争作用.
The mechanism of interaction between γ-cyclodextrin-neutral red (γ-CD-NR) inclusion complex and herring sperm DNA was studied by UV-Vis and fluorescence spectra. The results suggest that the intercalation and electrostatic binding should be the two major modes for the interaction between γ-CD-NR and DNA. It were confirmed by molar ratio method and double reciprocal method that the binding ratio of nγ-CD : nNR = 1 : 1 and the binding constant of Kf = 2.08 × 10^3 L· mol^-1. While the binding ratio of nγ-cD-NR : nDNA =4:1 and the binding constant of K25℃ =2.11× 10^6L·mol^-1. Thermodynamic function computation demonstrated that entropy (△rSm ) is the primary driving power of the interaction between γ-CD-NR and DNA. The results suggest that there are competitive action between γ-CD-NR inclusion complex and AO when they interact with DNA.