Synthesis of sulfur-rich nitrogen dots from a single source precursor and its application in dual-mode sensing.
Synthesis of sulfur-rich nitrogen dots from a single source precursor and its application in dual-mode sensing.
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DOI：
10.1016/j.talanta.2018.11.079
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发表时间：
2019-04
期刊：
影响因子：
6.1
通讯作者：
Zhijiao Tang;Jiani Yang;Gongke Li;Yuling Hu
中科院分区：
文献类型：
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作者：
Zhijiao Tang;Jiani Yang;Gongke Li;Yuling Hu
在这项工作中，发展了一种基于单源前体的富硫掺杂氮点(S-氮点)策略，并将其应用于汞离子的传感。以2-氮噻唑为单一前驱体，同时作为碳源、氮源和硫源，采用微波辅助法合成了S纳米荧光纳米粒子。这种SSP方法保证了高效的核心掺杂，并在分子水平上提高了掺杂效果，比多前驱体掺杂策略更高效、更简单。结果表明，合成的S网点硫含量高达24.6%，其独特的结构有效地促进了人工过氧化物酶活性和配位相互作用。有趣的是，Hg2+能明显猝灭S-Ndots的荧光强度，并选择性地抑制其过氧化物酶活性，然后将S-Ndots应用于Hg2+的荧光和比色读出的双模传感。该方法简便、快速，对Hg2+具有较高的选择性，荧光检测下限为0.1molmoL/L，肉眼可观察到明显的颜色变化。通过对工业废水中汞离子的定量检测，对方法的准确度和精密度进行了评价，结果令人满意。此外，还进一步探索了具有良好生物相容性的S核素在A549细胞中对Hg2+的成像。S量子点作为氮量子点家族的新成员，在环境和生物传感领域有着广阔的应用前景。
In this work, a strategy of sulfur-rich doped nitrogen dots (S-Ndots) based on a single-source precursor (SSP) was developed and applied to sensing of Hg2+. Fluorescent S-Ndots were synthesized by microwave-assisted method using 2-azidothiazole as a single-source precursor, which served as carbon, nitrogen and sulfur source simultaneously. This SSP approach guarantee efficient core doping and improve the effect of doping in a molecular level, which is more efficient and simpler than the doping strategy with multiple precursors. The results showed that the as-synthesized S-Ndots have high sulfur component up to 24.6%, and their specific structure effectively promoted artificial peroxidase activity and coordination interaction. Interestingly, the fluorescence intensity could be quenched obviously and the peroxidase activity of the S-Ndots were selectively inhibited by Hg2+, then the S-Ndots were applied to the dual-mode sensing of Hg2+with both fluorometric and colorimetric readout. The S-Ndots-based sensing assay with simplicity and rapidity showed high selectivity to Hg2+with the detection limit of 0.1 μmol/L by fluorescence spectroscopy and a distinguishable change in the color was observed by the naked eye. In addition, the accuracy and precision were evaluated based on the quantitative detection of Hg2+in industrial waste water samples with satisfactory results. Moreover, the S-Ndots with good biocompatibility were further explored for imaging of Hg2+in A549 cells. As a novel member of nitrogen quantum dots family, the S-Ndots hold great promise to broaden its applications in environmental and biological sensing.