Department of Chemistry, East China Normal University, Shanghai, PR China.
Anal Chim Acta. 2012 Jan 20;711:91-6. doi: 10.1016/j.aca.2011.10.053. Epub 2011 Nov 4.
In this paper, we report a novel and sensitive optical sensing protocol for thrombin detection based on magnetic nanoparticles (MNPs) and thrombin aptamer, employing split HRP-mimicking DNAzyme halves as its sensing element, which can catalyze the H(2)O(2)-mediated oxidation of the colorless ABTS into a blue-green product. A single nucleotide containing the recognition element and sensing element is utilized in our protocol. The specific recognition of thrombin and its aptamer leads to the structure deformation of the DNA strands and causes the split of the DNAzyme halves. Therefore, the decrease of absorption spectra can be recorded by the UV-visible Spectrophotometer. DNA-coated MNPs are utilized to separate the interferential materials from the analyst, thus making this assay can be applied in the detection of thrombin in complex samples, such as human plasma. This original, sensitive and cost-effective assay showed favorable recognition for thrombin. The absorbance signals with the concentration of thrombin over a range from 0.5 to 20 nM and the detection limit of thrombin was 0.5 nM. The controlled experiments showed that thrombin signal was not interfered in the presence of other co-existence proteins.
在本文中，我们报告了一种基于磁性纳米粒子（MNPs）和凝血酶适体的新型灵敏光学传感协议，用于凝血酶检测，该协议采用分裂的 HRP 模拟 DNA 酶作为其传感元件，可催化无色 ABTS 在 H（2）O（2）介导下氧化为蓝绿色产物。我们的方案中使用了包含识别元件和传感元件的单个核苷酸。凝血酶及其适体的特异性识别导致 DNA 链的结构变形，并导致 DNA 酶的分裂。因此，可以通过紫外可见分光光度计记录吸收光谱的下降。DNA 包覆的 MNPs 用于将干扰物质与分析物分离，从而使该测定法可应用于复杂样品（如人血浆）中凝血酶的检测。这种原始的、灵敏的和具有成本效益的测定法对凝血酶具有良好的识别能力。凝血酶浓度在 0.5 至 20 nM 范围内的吸光度信号，凝血酶的检测限为 0.5 nM。对照实验表明，在存在其他共存蛋白的情况下，凝血酶信号不会受到干扰。
