Ascorbic acid induced enhancement of room temperature phosphorescence of sodium tripolyphosphate-capped Mn-Doped ZnS quantum dots: mechanism and bioprobe applications.
Ascorbic acid induced enhancement of room temperature phosphorescence of sodium tripolyphosphate-capped Mn-Doped ZnS quantum dots: mechanism and bioprobe applications.
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DOI：
10.1002/chem.201001093
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发表时间：
2010-11
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影响因子：
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通讯作者：
He-Fang Wang;Yan Li;Ye-Yu Wu;Yu He;Xiu‐Ping Yan
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文献类型：
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作者：
He-Fang Wang;Yan Li;Ye-Yu Wu;Yu He;Xiu‐Ping Yan
尽管基于量子点（QD）的室温磷光（RTP）探针在诸如环境、食品和生物样品等复杂基质中的实际应用是有希望的，但是现有的基于QD的RTP探针不仅非常有限，而且完全基于RTP猝灭机制。在这里，我们报告了抗坏血酸（AA）诱导的磷光增强三聚磷酸钠覆盖的锰掺杂ZnS量子点，及其应用于开启RTP检测。螯合能力允许AA从量子点的表面提取Mn和Zn并产生更多的随后被Mn（2+）捕获的空穴，而还原性质允许AA将处于激发态的Mn（3+）还原为Mn（2+），从而增强量子点的激发和橙子发射。在0.05-0.8 μM范围内，增强的RTP强度随AA浓度的增加而线性增加。因此，基于量子点的RTP探针AA的开发。所提出的基于量子点的开启RTP探针避免了繁琐的样品预处理，并且在生物流体中的主要相关金属离子和其他分子的存在下为AA提供了良好的灵敏度和选择性。所开发方法的检测限（3s）为9 nM AA，对0.1 μM AA进行11次重复检测的相对标准偏差为4.8%。该方法已成功地应用于人体尿液和血浆中AA的真实的样品分析，定量回收率为96 - 105%。
Although quantum dot (QD)-based room temperature phosphorescence (RTP) probes are promising for practical applications in complex matrixes such as environmental, food and biological samples, current QD-based-RTP probes are not only quite limited but also exclusively based on the RTP quenching mechanism. Here we report an ascorbic acid (AA) induced phosphorescence enhancement of sodium tripolyphosphate-capped Mn-doped ZnS QDs, and its application for turn-on RTP detection. The chelating ability allows AA to extract the Mn and Zn from the surface of the QDs and to generate more holes which are subsequently trapped by Mn(2+), while the reducing property permits AA to reduce Mn(3+) to Mn(2+) in the excited state, thereby enhancing the excitation and orange emission of the QDs. The enhanced RTP intensity of the QDs increases linearly with the concentration of AA in the range of 0.05-0.8 μM. Thus, a QD-based RTP probe for AA is developed. The proposed QD-based turn-on RTP probe avoids tedious sample pretreatment, and offers good sensitivity and selectivity for AA in the presence of the main relevant metal ions and other molecules in biological fluids. The limit of detection (3s) of the developed method is 9 nM AA, and the relative standard deviation is 4.8 % for 11 replicate detections of 0.1 μM AA. The developed method is successfully applied to the analysis of real samples of human urine and plasma for AA with quantitative recoveries from 96 to 105 %.