Yue Guiyin, Ye Huazhen, Huang Xijing, Ye Wenmei, Qiu Suyan, Qiu Bin, Lin Zhenyu, Chen Guonan
MOE Key Laboratory of Analysis and Detection for Food Safety, Fujian Provincial Key Laboratory of Analysis and Detection Technology for Food Safety, Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, China.
Analyst. 2014 Nov 21;139(22):5669-73. doi: 10.1039/c4an01438c.
A simple, sensitive and selective fluorescence biosensor for determination of DNA using CuS particles based on click chemistry is reported. Biotin-modified capture DNA was modified on Streptavidin MagneSphere Paramagnetic Particles (PMPs) and hybridized with target DNA (hepatitis B virus DNA had been chosen as an example), then bound target DNA was hybridized with DNA-CuS particles and formed a sandwich like structure. CuS particles on the sandwich structures can be destroyed by acid to form Cu(II), and Cu(II) can be reduced to Cu(I) by sodium ascorbate, which in turn catalyzes the reaction between a weak-fluorescent 3-azido-7-hydroxycoumarin and propargyl alcohol to form a fluorescent 1,2,3-triazole compound. Using this method, target DNA concentration can be determined by a change in the fluorescence intensity of the system. It is found that the fluorescence increase factor has a direct linear relationship to the logarithm of target DNA concentrations in the range of 0.1 to 100 nM, and the detection limit is 0.04 nM (S/N = 3). The proposed sensor not only allows high sensitivity and good reproducibility, but also has a good selectivity to single-nucleotide mismatches.
报道了一种基于点击化学、用于测定DNA的简单、灵敏且具有选择性的荧光生物传感器。生物素修饰的捕获DNA被修饰在链霉亲和素磁珠顺磁性颗粒（PMPs）上，并与靶标DNA（以乙型肝炎病毒DNA为例）杂交，然后结合的靶标DNA与DNA-CuS颗粒杂交，形成类似三明治的结构。三明治结构上的CuS颗粒可被酸破坏形成Cu(II)，Cu(II)可被抗坏血酸钠还原为Cu(I)，Cu(I)进而催化弱荧光的3-叠氮基-7-羟基香豆素与炔丙醇之间的反应，形成荧光1,2,3-三唑化合物。利用该方法，可通过系统荧光强度的变化来测定靶标DNA浓度。研究发现，在0.1至100 nM范围内，荧光增强因子与靶标DNA浓度的对数呈直接线性关系，检测限为0.04 nM（S/N = 3）。所提出的传感器不仅具有高灵敏度和良好的重现性，而且对单核苷酸错配具有良好的选择性。
