Luminescent carbon dots (CDs) have become attractive materials because of their superior photophysical properties and various potential applications. However, most of the formerly developed CDs only have strong blue emission, which limits their further applications, particularly in bioimaging. Herein luminescent CDs have been successfully synthesized via a one-pot solvothermal process using 4-bromoaniline and ethylenediamine as starting materials. The luminescent CDs emit strong green fluorescence with high quantum yield as well as excellent biocompatibility and biolabeling potentials. At first, the luminescent CDs exhibited high selectivity for phosgene with a turn-off fluorescence detection. The limit of detection was 81 nM, which is sensitive for the determination of phosgene over other competing toxic pollutants. In addition, the luminescent CDs have shown a three-state “on–off–on” emission with the stepwise addition of Ag⁺ and cysteine (Cys). Luminescent CDs show fluorescence quenching by Ag⁺ and fluorescence regaining with further addition of Cys, with lower detection limits of 3.9 μM (Ag⁺) and 3.4 μM (Cys), respectively. The luminescent CDs were utilized to obtain a clear fingerprint. During the drying process, the coffee ring effect and electrostatic interaction between the positive surface charge of amine-functionalized CDs and negatively charged fingerprint residues facilitate the formation of clear fingerprints on different platforms.

中文翻译：

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用于活细胞多功能选择性传感和成像应用的明亮发光碳点

发光碳点 (CD) 因其优越的光物理性能和各种潜在应用而成为有吸引力的材料。然而，大多数以前开发的 CD 仅具有强烈的蓝光发射，这限制了它们的进一步应用，特别是在生物成像方面。在此，使用 4-溴苯胺和乙二胺作为起始材料，通过一锅溶剂热法成功合成了发光 CD。发光 CD 发出强烈的绿色荧光，具有高量子产率以及优异的生物相容性和生物标记潜力。首先，发光CDs对光气表现出高选择性，具有关闭荧光检测。检测限为 81 nM，这对于测定光气而不是其他竞争性有毒污染物非常敏感。此外，⁺和半胱氨酸 (Cys)。发光 CD 显示 Ag ⁺的荧光猝灭和进一步添加 Cys 的荧光恢复，检测限分别为 3.9 μM (Ag ⁺ ) 和 3.4 μM (Cys)。发光CD用于获得清晰的指纹。在干燥过程中，胺官能化CD的正表面电荷与带负电荷的指纹残基之间的咖啡环效应和静电相互作用有助于在不同平台上形成清晰的指纹。