Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433, P. R. China.
Nanoscale. 2014 Nov 21;6(22):13817-23. doi: 10.1039/c4nr04267k.
Sulfur-doped carbon dots (S-CDs) with a quantum yield (QY) of 5.5% and nitrogen, sulfur co-doped carbon dots (N,S-CDs) with a QY of 54.4% were synthesized, respectively, via the same hydrothermal route using α-lipoic acid as the carbon source. The obtained S-CDs and N,S-CDs had similar sizes but different optical features. The QY of N,S-CDs was gradually enhanced when extending the reaction time to increase the nitrogen content. After careful characterization of these CDs, the doped nitrogen element was believed to be in the form of C=N and C-N bonds which enhanced the fluorescence efficiency significantly. Meanwhile, the co-doped sulfur element was found to be synergistic for nitrogen doping in N,S-CDs. The optimal N,S-CDs were successfully employed as good multicolor cell imaging probes due to their fine dispersion in water, excitation-dependent emission, excellent fluorescence stability and low toxicity. Besides, such N,S-CDs showed a wide detection range and excellent accuracy as fluorescent sensors for Fe(3+) ions.
分别通过相同的水热路线，以硫辛酸为碳源，合成量子产率为 5.5%的硫掺杂碳点（S-CDs）和量子产率为 54.4%的氮、硫共掺杂碳点（N,S-CDs）。所得 S-CDs 和 N,S-CDs 具有相似的尺寸，但光学性质不同。随着反应时间的延长，氮含量增加，N,S-CDs 的量子产率逐渐增强。对这些 CD 进行仔细表征后，认为掺杂的氮元素以 C=N 和 C-N 键的形式存在，这显著提高了荧光效率。同时，共掺杂的硫元素在 N,S-CDs 中对氮掺杂具有协同作用。由于最佳 N,S-CDs 在水中具有良好的分散性、激发依赖性发射、优异的荧光稳定性和低毒性，因此成功用作良好的多色细胞成像探针。此外，这些 N,S-CDs 作为荧光传感器对 Fe(3+)离子具有较宽的检测范围和优异的准确性。
