阳离子荧光共轭聚合物结合纳米颗粒用于DNA检测

Detection of Deoxyribonucleic Acid Using Cationic Fluorescent Conjugated Polymer and Nanoparticles

利用纳米颗粒对目标DNA的富集、分离作用以及阳离子荧光共轭聚合物良好的荧光特性,建立了一种特异性检测DNA的新方法。首先将标记有猝灭基团的DNA捕获探针修饰到纳米颗粒上,捕获互补的DNA分子;然后加入S1核酸酶,除去未捕获到互补DNA的捕获探针;最后用DNaseⅠ将颗粒上的双链切断,使猝灭基团从纳米颗粒上解离下来,与阳离子荧光共轭聚合物结合并猝灭其荧光。结果表明,目标核酸的浓度与该聚合物的荧光猝灭程度正相关,且具有良好的特异性,线性响应范围为5.0～40nmol/L;检出限为3.7nmol/L(S/N=3)。

A novel method for DNA detection was developed based on the excellent fluorescence properties of cationic conjugated polymer （CCP） and the target DNA enrichment, separation function of nanoparticles. First, the quencher-labeled DNA capture probes were modified on the surface of Au nanoparticles, and complementary DNA strands were captured. Second, S1 nuclease was added, and the capture probes that had not captured the complementary DNA were removed from the nanoparticles. Finally, the complementary doublestranded DNA was cut by DNase I, the quenchers were dissociated from nanopartiele and the fluorescence of CCP was quenched by means of combination of quenchers and CCP. The results showed that this method is specific. In the range of 5.0 - 40 nmol/L, the concentration of target DNA was proportional to the fluorescence quenching and the detection limit was 3.7 nmol/L（S/N = 3）.