基于诺氟沙星-Tb3+配合物与DNA之间的相互作用对DNA进行灵敏测定。
Sensitive determination of DNA based on the interaction between norfloxacin-Tb3+ complex and DNA.
作者信息
Tong Changlun, Hu Zhou, Liu Weiping
机构信息
Institute of Environmental Science, Zhejiang University, Hangzhou 310029, China.
出版信息
J Agric Food Chem. 2005 Aug 10;53(16):6207-12. doi: 10.1021/jf050783d.
The fluorescence intensity of the norfloxacin (NFX)-Tb3+ complex enhanced by DNA was studied. Therefore, a sensitive fluorescence method for the determination of DNA was developed. The optimal conditions of the method were as follows: the hexamethylenamine (HMA)-HCl buffer was adopted for adjusting the pH to 6.5 +/- 0.1, the concentrations of NFX and Tb3+ were both fixed in 1.0 x 10(-6) mol L(-1), and the excitation and emission wavelengths were selected at 290 and 545 nm, respectively. Under the optimal conditions, the enhanced fluorescence intensity was in proportion to the concentration of DNA in the same range of 5.0 x 10(-9) - 1.0 x 10(-6) g mL(-1) for hsDNA and thermally denatured ctDNA. The detection limits (S/N = 3) were 0.9 and 0.6 ng mL(-1), respectively. In addition, the interaction between NFX-Tb3+ and DNA was discussed in detail. The experimental results from UV absorption spectra, fluorescence spectra, and the salt effect study indicated that the interaction between norfloxacin-Tb3+ complex and DNA had at least two different binding modes: the electrostatic binding and the intercalation binding. The mechanism of the fluorescence enhancement effect was also discussed.
研究了DNA增强诺氟沙星（NFX）-Tb3+配合物的荧光强度。因此，建立了一种灵敏的测定DNA的荧光方法。该方法的最佳条件如下：采用六亚甲基胺（HMA）-HCl缓冲液将pH调至6.5±0.1，NFX和Tb3+的浓度均固定为1.0×10−6 mol L−1，激发波长和发射波长分别选择为290和545 nm。在最佳条件下，对于热变性的小牛胸腺DNA（ctDNA）和人血清DNA（hsDNA），增强的荧光强度在5.0×10−9 - 1.0×10−6 g mL−1的相同范围内与DNA浓度成正比。检测限（S/N = 3）分别为0.9和0.6 ng mL−1。此外，还详细讨论了NFX-Tb3+与DNA之间的相互作用。紫外吸收光谱、荧光光谱和盐效应研究的实验结果表明，诺氟沙星-Tb3+配合物与DNA之间的相互作用至少有两种不同的结合模式：静电结合和嵌入结合。还讨论了荧光增强效应的机制。
Zotero 插件