Ultrasensitive DNAzyme based amperometric determination of uranyl ion using mesoporous silica nanoparticles loaded with Methylene Blue
Ultrasensitive DNAzyme based amperometric determination of uranyl ion using mesoporous silica nanoparticles loaded with Methylene Blue
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使用负载亚甲基蓝的介孔二氧化硅纳米粒子基于超灵敏 DNAzyme 的安培测定铀酰离子
DOI：
10.1007/s00604-017-2397-7
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发表时间：
2017-10-01
影响因子：
5.7
通讯作者：
Hou, Shaoyan
中科院分区：
文献类型：
--
作者：
Wen, Yi;Yuan, Yali;Hou, Shaoyan
本文介绍了一种超灵敏的测定铀酰离子的安培法。它的基础是使用介孔二氧化硅纳米颗粒(MesoSiNPs)负载亚甲基蓝(MB)，并用UO2(II)依赖的DNAzyme功能化。电活性标记MB与双链DNA(包括DNAzyme和底物链)一起封闭在介孔SiNPs的内孔中。在UO2(II)存在下，DNAzyme被激活以切割底物链。这导致了帽的断裂和MB从介观SiNPs中的释放。MB的释放量取决于UO_2(II)的浓度，可用电流法测定，在工作电压为0.25nV(VsSCE)时，用壳聚糖包覆的碳糊电极测定效果最佳。在20~0.1nM的UO2(II)浓度范围内，响应呈线性关系，检测下限低至0.15 pm加标样品的回收率在91.3%~99.4%之间。该分析具有高度的特异性和选择性，不受其他金属离子的干扰。图形摘要(A)介孔SiNPs的合成、MB的负载和dsDNA结合的示意图，以及在UO22+存在下介孔SiNPs释放MB的示意图。(B)用于铀检测的分步DNAzyme电化学传感器示意图。
The authors describe an ultrasensitive amperometric enzymatic assay for uranyl ion. It is based on the use of mesoporous silica nanoparticles (mesoSiNPs) loaded with Methylene Blue (MB) and functionalized with an UO2(II)-dependent DNAzyme. The electroactive label MB was sealed in the inner pores of the mesoSiNPs along with double stranded DNA (containing the DNAzyme and the substrate strand). In the presence of UO2(II), the DNAzyme is actived to cleave the substrate strands. This leads to the cleavage of the caps and the release of MB from the mesoSiNPs. The amount of released MB depends on the concentration of UO2(II) and can be determined amperometrically, best at a working voltage of −0.25 V (vs SCE), by using a chitosan coated carbon paste electrode. Response is linear in the 20 pM to 0.1 nM UO2(II) concentration range, and the detection limit is as low as 0.15 pM. Recoveries from spiked samples varied from 91.3 to 99.4%. The assay is highly specific, selective, and not interfered by other metal ions.Graphical abstract(a)Schematic representation of the synthesis, MB loading, and dsDNA Binding of the mesoSiNPs, as well as the release of MB from mesoSiNPs in the presence of UO22+.(b)Schematic illustration of the stepwise DNAzyme-based electrochemical sensor for uranium detection.