The lysosome-targeting carbon dots (CDs) with excellent water solubility and strong blue emission were synthesized through a one-step functional modification for long-term lysosome imaging in living cells. Based on the carboxyl-rich CDs synthesized by oxidizing carbon black in refluxing HNO₃, then N,N-dimethylethylenediamine (DMEDA) was chemically linked onto the CDs through acylation reaction to obtain DMEDA modified carbon dots (M-CDs). The infrared spectrum of M-CDs showed the characteristic peak of acylamide (O=C–NH–) at 1658 cm⁻¹, indicating the successful modification of DMEDA. The quantum yield of M-CDs was 15.6%, which was 27 times higher than the initial carboxyl rich CDs, meeting the requirement of cell imaging. The probe entered cells through the temperature-dependent endocytosis way and the co-localization experiment with commercial dye Lyso-Tracker red showed that the probe localized in lysosomes and could be used as a universal lysosome tracker in different cell lines. Moreover, compared to commercially available Lyso-Tracker blue, M-CDs were more photostable under UV light. The fluorescence of M-CDs was still brightness after time-lapsed imaging by confocal microscopy for 120 min with an interval of 5 min in living cells, implying that the M-CDs could be used for long-term imaging of lysosomes.

通过一步功能修饰合成了具有优异水溶性和强蓝色发射的溶酶体靶向碳点（CD），用于活细胞中的长期溶酶体成像。基于在回流HNO _{3 中}氧化炭黑合成的富含羧基的CDs ，然后通过酰化反应将N,N-二甲基乙二胺(DMEDA)化学连接到CDs上以获得DMEDA改性碳点(M-CDs)。M-CDs的红外光谱在1658 cm ^-1处显示了酰胺(O=C-NH-)的特征峰，说明DMEDA修改成功。M-CDs的量子产率为15.6%，是初始富羧基CDs的27倍，满足细胞成像的要求。该探针通过温度依赖性内吞作用进入细胞，与商业染料 Lyso-Tracker red 的共定位实验表明，该探针定位于溶酶体，可作为不同细胞系中的通用溶酶体示踪剂。此外，与市售的 Lyso-Tracker blue 相比，M-CD 在紫外线下更耐光。M-CDs 的荧光在共聚焦显微镜延时成像 120 分钟后仍然是明亮的，间隔 5 分钟在活细胞中，这意味着 M-CDs 可用于溶酶体的长期成像。