Huang Shan, Zhu Fawei, Qiu Hangna, Xiao Qi, Zhou Quan, Su Wei, Hu Baoqing
College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China.
College of Chemistry and Life Science, Guangxi Teachers Education University, Nanning 530001, PR China.
Colloids Surf B Biointerfaces. 2014 May 1;117:240-7. doi: 10.1016/j.colsurfb.2014.02.031. Epub 2014 Feb 28.
In this contribution, a simple and sensitive fluorescent sensor for the determination of both the three ruthenium anticancer drugs (1 to 3) and calf thymus DNA (ctDNA) was established based on the CdTe quantum dots (QDs) fluorescence "OFF-ON" mode. Under the experimental conditions, the fluorescence of CdTe QDs can be effectively quenched by ruthenium anticancer drugs because of the surface binding of these drugs on CdTe QDs and the subsequent photoinduced electron transfer (PET) process from CdTe QDs to ruthenium anticancer drugs, which render the system into fluorescence "OFF" status. The system can then be "ON" after the addition of ctDNA which brought the restoration of CdTe QDs fluorescence intensity, since ruthenium anticancer drugs broke away from the surface of CdTe QDs and inserted into double helix structure of ctDNA. The fluorescence quenching effect of the CdTe QDs-ruthenium anticancer drugs systems was mainly concentration dependent, which could be used to detect three ruthenium anticancer drugs. The limits of detection were 5.5 × 10(-8) M for ruthenium anticancer drug 1, 7.0 × 10(-8) M for ruthenium anticancer drug 2, and 7.9× 10(-8) M for ruthenium anticancer drug 3, respectively. The relative restored fluorescence intensity was directly proportional to the concentration of ctDNA in the range of 1.0 × 10(-8) M ∼ 3.0 × 10(-7) M, with a correlation coefficient (R) of 0.9983 and a limit of detection of 1.1 × 10(-9) M. The relative standard deviation (RSD) for 1.5 × 10(-7) M ctDNA was 1.5% (n = 5). There was almost no interference to some common chemical compounds, nucleotides, amino acids, and proteins. The proposed method was applied to the determination of ctDNA in three synthetic samples with satisfactory results. The possible reaction mechanism of CdTe QDs fluorescence "OFF-ON" was further investigated. This simple and sensitive approach possessed some potential applications in the investigation of interaction between drug molecules and DNA.
在本研究中，基于碲化镉量子点（QDs）荧光“关-开”模式，建立了一种用于同时测定三种钌抗癌药物（1至3）和小牛胸腺DNA（ctDNA）的简单且灵敏的荧光传感器。在实验条件下，钌抗癌药物可有效猝灭碲化镉量子点的荧光，这是因为这些药物在碲化镉量子点表面结合，随后发生从碲化镉量子点到钌抗癌药物的光致电子转移（PET）过程，使体系进入荧光“关”状态。加入ctDNA后，体系可转变为“开”状态，此时碲化镉量子点荧光强度恢复，这是由于钌抗癌药物从碲化镉量子点表面脱离并插入ctDNA的双螺旋结构中。碲化镉量子点-钌抗癌药物体系的荧光猝灭效应主要取决于浓度，可用于检测三种钌抗癌药物。钌抗癌药物1、2、3的检测限分别为5.5×10⁻⁸ M、7.0×10⁻⁸ M和7.9×10⁻⁸ M。相对荧光恢复强度与ctDNA浓度在1.0×10⁻⁸ M至3.0×10⁻⁷ M范围内成正比，相关系数（R）为0.9983，检测限为1.1×10⁻⁹ M。1.5×10⁻⁷ M ctDNA的相对标准偏差（RSD）为1.5%（n = 5）。对一些常见化合物、核苷酸、氨基酸和蛋白质几乎没有干扰。该方法应用于三个合成样品中ctDNA的测定，结果令人满意。进一步研究了碲化镉量子点荧光“关-开”的可能反应机理。这种简单灵敏的方法在药物分子与DNA相互作用研究中具有一些潜在应用。
