Key Laboratory of Sensor Analysis of Tumor Marker, Ministry of Education, Shandong Key Laboratory of Biochemical Analysis, Key Laboratory of Analytical Chemistry for Life Science in Universities of Shandong, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao, 266042, People's Republic of China.
Mikrochim Acta. 2019 Jul 19;186(8):551. doi: 10.1007/s00604-019-3683-3.
A highly sensitive fluorometric method is described for the determination of mercury(II) ions. It is based on (a) the use of a DNA probe containing thymine-thymine mismatches that are employed as Hg(II) recognition elements, (b) subsequent toehold binding, and (c) endocuclease-assisted signal amplification. Target recycling is triggered by exonuclease III. This produces a large amount of ssDNA (defined as primer). Then, the generated primer-initiated strand displacement reaction with the help of polymerase and nicking endonuclease releases the free fluorophore-labelled probe. Under excitation at 532 nm, the fluorescent probe displays emission with a peak at 582 nm. The sensitivity of this method is improved by introduction of nicking endonuclease. The working range of the assay extends from 20 pM to 10 nM, and the detection limit is as low as 6 pM of Hg(II). Graphical abstract Schematic presentation of the fluorometric method for determination of mercury(II). By using a special structure of thymine-thymine mismatches, target-induced toehold binding and enzyme-assisted signal amplification strategy were employed. This method is selective and good performance in real sample application.
一种高灵敏度的荧光测定法用于测定汞（II）离子。它基于（a）使用含有胸腺嘧啶-胸腺嘧啶错配的 DNA 探针，该错配用作 Hg（II）识别元件，（b）随后的引发结合，和（c）内切酶辅助的信号放大。通过外切酶 III 触发靶标循环。这产生了大量的单链 DNA（定义为引物）。然后，在聚合酶和切口内切酶的帮助下，生成的引物引发链置换反应，释放出游离的荧光标记探针。在 532nm 的激发下，荧光探针在 582nm 处显示出发射峰。通过引入切口内切酶提高了该方法的灵敏度。测定法的工作范围从 20 pM 扩展到 10 nM，检测限低至 6 pM 的 Hg（II）。
