Rhodamine‐B grafted carbon dots (RhB‐CDs) with double emission fluorescence are developed , one of which has excitation dependence, while the other have not. The prepared RhB‐CDs have good dispersibility, uniform spherical shape, and excellent water solubility. They could be used to specifically detect Fe3+ ions in an aqueous solution with the detection limit of 1.1 × 10−6 m and with good anti‐interference ability, because Fe3+ ions are easier to combine with hydroxyl groups on the surface of RhB‐CDs to form aggregates (such as ferric hydroxide) than other metal ions, which lead to the fluorescence quenching of RhB‐CDs. Fe3+ ions not only quench the fluorescence intensity of both double emission peaks of RhB‐CDs, but also change the relative fluorescence intensity of these two fluorescence emission peaks. Therefore, two different fluorescence analysis methods are used to specifically identify iron ions and the results are consistent with each other. At the same time, the double emission fluorescent RhB‐CDs have low hemolysis rate and cytotoxicity, indicating that RhB‐CDs do little harm to cells and are further used to detect Fe3+ ions in cells through fluorescence bioimaging. All of the above indicates that the prepared RhB‐CDs would have potential application value in detecting iron ions in blood and cells.

中文翻译：

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罗丹明-B 接枝双发射荧光碳点用于细胞内铁离子的选择性检测和生物成像

开发了具有双发射荧光的罗丹明-B接枝碳点（RhB-CD），其中一种具有激发依赖性，而另一种则没有。制备的RhB-CDs具有良好的分散性、均匀的球形和优异的水溶性。它们可用于专门检测铁3+水溶液中离子的检测限为1.1 × 10−6 米并且具有良好的抗干扰能力，因为Fe3+与其他金属离子相比，RhB-CDs更容易与RhB-CDs表面的羟基结合形成聚集体（如氢氧化铁），从而导致RhB-CDs的荧光猝灭。铁3+离子不仅猝灭RhB-CDs两个双发射峰的荧光强度，而且改变了这两个荧光发射峰的相对荧光强度。因此，采用两种不同的荧光分析方法来特异性识别铁离子，结果是一致的。同时，双发射荧光RhB-CDs具有较低的溶血率和细胞毒性，表明RhB-CDs对细胞伤害较小，可进一步用于Fe的检测。3+通过荧光生物成像检测细胞中的离子。这些都表明制备的RhB-CDs在检测血液和细胞中的铁离子方面具有潜在的应用价值。