\r袁才登^{1, 2}，杨盼星¹，苏 洁¹，郭睿威^{1, 2}，姚芳莲\r^{1, 2}\r
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AuthorsHTML:\r袁才登^{1, 2}，杨盼星¹，苏 洁¹，郭睿威^{1, 2}，姚芳莲\r^{1, 2}\r
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AuthorsListE:\rYuan Caideng^{1, 2}，Yang Panxing¹，Su Jie¹，Guo Ruiwei^{1, 2}，Yao Fanglian\r^{1, 2}\r
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AuthorsHTMLE:\rYuan Caideng^{1, 2}，Yang Panxing¹，Su Jie¹，Guo Ruiwei^{1, 2}，Yao Fanglian\r^{1, 2}\r
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Unit:\r\r1. 天津大学化工学院，天津 300350；\r
\r\r2. 天津大学-隆泰丰博石墨烯应用联合研究中心，天津 300350\r
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Unit_EngLish:\r1. School of Chemical Engineering and Technology，Tianjin University，Tianjin 300350，China；
2. Tianjin University-UCGM Joint Research Center for Graphene Application，Tianjin 300350，China\r
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Abstract_Chinese:\r\r以柠檬酸、乙二胺和苯硼酸为原料，采用一步水热法制备了高荧光量子产率、长荧光寿命的硼氮共掺杂石墨烯量子点\r(\rB\r，\rN\r-\rGQDs\r)\r．通过透射电子显微镜\r(\rTEM\r)\r、傅里叶变换红外光谱仪\r(\rFT\r-\rIR\r)\r、\rX\r射线光电子能谱仪\r(\rXPS\r)\r、紫外\r-\r可见分光光度计\r(\rUV\r-\rVis\r)\r及荧光光谱仪\r(\rPL\r)\r对量子点进行了表征．结果表明，\rB\r，\rN\r-\rGQDs\r粒径范围为\r1.46\r～\r3.54nm\r，平均粒径为\r(\r2.34\r±\r0.50\r)\rnm\r，具有明显的晶格条纹结构；表面官能团\r(\r—\rOH\r，\r—\rNH\r和\r—\rBOH\r)\r的存在，有利于与金属离子结合从而实现对金属离子的检测；在\rpH\r＝\r5.0\r～\r10.0\r和\rNaCl\r浓度\r0\r～\r1.0mol/L\r的酸碱盐环境下，\rB\r，\rN\r-\rGQDs\r具有优异的荧光稳定性．由于\rB\r，\rN\r-\rGQD\r与金属离子具有结合作用，因此它被用作检测金属离子的荧光探针．考察了\r15\r种金属离子\r(\rK\r^\r+\r\r、\rNa\r^\r+\r\r、\rBa²\r^\r+\r\r、\rNi²\r^\r+\r\r、\rZn²\r^\r+\r\r、\rPb²\r^\r+\r\r、\rLi\r^\r+\r\r、\rCu²\r^\r+\r\r、\rAg\r^\r+\r\r、\rMn²\r^\r+\r\r、\rFe²\r^\r+\r\r、\rMg²\r^\r+\r\r、\rFe³\r^\r+\r\r、\rCa²\r^\r+\r\r和\rHg²\r^\r+\r\r)\r对\rB\r，\rN\r-\rGQDs\r荧光强度的影响，发现仅\rMg²\r^\r+\r\r、\rFe³\r^\r+\r\r、\rCa²\r^\r+\r\r和\rHg²\r^\r+\r\r对其荧光有猝灭作用．考虑到\rHg²\r^\r+\r\r是重要的有毒污染物，因此灵敏、选择性地检测\rHg²\r^\r+\r\r对人体健康和环境保护至关重要．在单一汞离子体系中，其线性范围为\r2.0\r～\r20.0μmol/L\r，检测限为\r0.05μmol/L\r；在复杂体系\r(\rMg²\r^\r+\r\r、\rFe³\r^\r+\r\r、\rCa²\r^\r+\r\r和\rHg²\r^\r+\r\r)\r中，采用掩蔽剂\rNaF\r能够实现对\rHg²\r^\r+\r\r浓度的准确测定，其检测误差范围为\r－\r4.432\r%\r～\r2.600\r%\r．\rB\r，\rN\r-\rGQDs\r有望在多金属离子响应体系中实现对\rHg²\r^\r+\r\r的快速检测．此外，探究了\rHg²\r^\r+\r\r对\rB\r，\rN\r-\rGQDs\r荧光的猝灭机理，当加入\rHg²\r^\r+\r\r后，\rB\r，\rN\r-\rGQDs\r的荧光寿命从原来的\r12.86ns\r缩短为\r11.34ns\r，符合动态猝灭机理．\r\r
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Abstract_English:\r\rIn this study\r，\rwe prepared \rboron-nitrogen co-doped graphene quantum dots \r(\rB\r，\rN-GQDs\r)\r with a high fluorescence quantum yield and long fluorescence lifetime using a one-step hydrothermal method and citric acid\r，\rethylenediamine\r，\rand phenylboronic acid as raw materials. We characterized and determined the structure and proper-ties of the B\r，\rN-GQDs by TEM\r，\rFT-IR\r，\rXPS\r，\rUV-Vis\r，\rand PL spectroscopy. The results show that the particle size range of B\r，\rN-GQDs is 1.46\r—\r3.54 nm\r，\rthe average particle size is \r(\r2.34±0.50\r)\r nm\r，\rand there is an obvious lattice fringe structure. To improve the detection of metal ions\r，\rit is beneficial to combine B\r，\rN-GQDs with metal ions due to the presence of its surface functional groups \r(\r—\rOH\r，—\rNH\r，\rand \r—\rBOH\r)\r. B\r，\rN-GQDs have excellent fluorescence stability in an environment with a pH\r＝\r5.0\r—\r10.0 and an NaCl concentration of 0\r—\r1.0 mol/L. Owing to their excel-lent affinity for interacting with metal ions\r，\rwe used B\r，\rN-GQDs as a fluorescent probe to detect metal ions. Herein\r，\rwe investigated the effects of fifteen metal ions \r(\rK⁺\r，\rNa⁺\r，\rBa²⁺\r，\rNi²⁺\r，\rZn²⁺\r，\rPb²⁺\r，\rLi⁺\r，\rCu²⁺\r，\rAg⁺\r，\rMn²⁺\r，\rFe²⁺\r，\rMg²⁺\r，\rFe³⁺\r，\rCa²⁺ and Hg²⁺\r\r)\r on the fluorescence of B\r，\rN-GQDs. We found that its fluorescence was quenched by Mg²⁺\r，\rFe³⁺\r，\rCa²⁺ and Hg²⁺. The sensitive and selective detection of Hg²⁺ is essential for human health and envi-ronmental protection as it was one of the most toxic and dangerous pollutants. We obtained a linear relationship between the decreased fluorescence intensity of B\r，\rN-GQDs and Hg²⁺ concentrations ranging from 2.0\r—\r20.0 μmol/L with a detection limit of 0.05 μmol/L. In this work\r，\rB\r，\rN-GQDs served as a multi-metal-ion responsive platform that could be used to directly detect Hg²⁺ from a complex system \r(\rMg²⁺\r，\rFe³⁺\r，\rCa²⁺ and Hg²⁺\r)\r by the masking agent NaF\r，\rwith a detection error in the range of \r-\r4.432% to 2.600%. As such\r，\rB\r，\rN-GQDs provided an original and fascinating fluorescent platform for effectively differentiating and selectively detecting Hg²⁺ among multi-metal ions. In addition\r，\rwe investigated the quenching mechanism of Hg²⁺ on B\r，\rN-GQDs fluorescence. When Hg²⁺ was added\r，\rthe fluorescence lifetime of B\r，\rN-GQDs was shortened from 12.86 ns to 11.34 ns\r，\rwhich accords with the dynamic quenching mechanism.\r\r
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Keyword_Chinese:石墨烯量子点；荧光；选择性；检测；污染物；汞离子\r

Keywords_English:graphene quantum dots；fluorescence；selectivity；detection；pollutant；Hg\r^2＋\r


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