Doping effect and fluorescence quenching mechanism of N-doped graphene quantum dots in the detection of dopamine
Doping effect and fluorescence quenching mechanism of N-doped graphene quantum dots in the detection of dopamine
复制标题
N掺杂石墨烯量子点在多巴胺检测中的掺杂效应及荧光猝灭机制
DOI：
10.1016/j.talanta.2019.01.001
复制
发表时间：
2019-05-01
期刊：
影响因子：
6.1
通讯作者：
Li, Y.
中科院分区：
文献类型：
--
作者：
Ma, Y.;Chen, A. Y.;Li, Y.
元素掺杂被认为是修饰石墨烯量子点表面缺陷结构和进一步增强其荧光性能的有效方法。合成了N掺杂、S掺杂和S、N共掺杂的GQD，探讨了元素掺杂对多巴胺（DA）生物分子荧光传感的影响。结果表明，以尿素为氮源的氮掺杂量子点的量子产率最高可达78%，且对DA具有灵敏的荧光猝灭性能，而以乙二胺为氮源的氮掺杂量子点的量子产率最高可达95%，但其荧光猝灭性能与硫掺杂和硫、氮共掺杂量子点的荧光猝灭性能相比有明显的提高。对DA无淬火性能，并根据显微组织分析对这一异常现象进行了讨论。在最佳反应条件下，N掺杂GQDs的荧光猝灭强度与DA浓度在10-3000 nM和3000-7000 nM范围内呈双线性关系，检测限分别为3.3和611 nM。从氮的化学状态、DA同系物的生物分子结构和DA的氧化还原反应等方面探讨了氮掺杂GQDs对DA的猝灭机理。
Element doping is recognized as a powerful way to modify surface defect structure and further enhance the fluorescence performance of graphene quantum dots (GQDs). N-doped, S-doped and S, N co-doped GQDs were synthesized to explore the influence of element doping on fluorescence sensing of dopamine (DA) biomolecules. Two interesting works are found, one is that the N-doped GQDs with urea as N source are more effective than the S-doped and S,N co-doped GQDs, characterized by the higher quantum yield (QY) up to 78% and sensitive fluorescence quenching performance to DA. The other is that the N-doped GQDs with ethylenediamine as N source have the highest QY up to 95%, however, exhibits no quenching performance to DA. This abnormal observation is discussed based on the microstructure analysis. Under the optimal reaction condition, the N-doped GQDs exhibit a dual linear relationship of quenching intensity with DA concentration in the range of 10-3000 nM and 3000-7000 nM with detection limits of 3.3 and 611 nM, respectively. The quenching mechanism of N-doped GQDs toward DA is explored from the view of N chemical states, biomolecule structure of DA homologues and redox reaction of DA.