Research Center for Analytical Sciences, Department of Chemistry, College of Sciences, Northeastern University, Box 332, Shenyang 110819, China.
Nanoscale. 2018 Jul 9;10(26):12788-12796. doi: 10.1039/c8nr03453b.
Organelles play crucial roles in cellular activities and the functions of organelles are related greatly to the pH values, therefore, the bio-imaging of targeted organelles and their related pH sensing is of great importance in biological assays. Herein we report the fluorescence imaging of specific organelles, i.e., lysosomes and endoplasmic reticulum, and their pH sensing with surface regulated carbon dots (CDs). Carbon dots functionalized with amine groups (ACDs) are first prepared by hydrothermal treatment of citric acid and urea, and then laurylamine functionalized CDs (LCDs) are obtained via the conjugation of laurylamine with ACDs. The as-prepared ACDs and LCDs provide clear and bright imaging results for the lysosome and endoplasmic reticulum, respectively. The subcellular targeting features of the two CDs are attributed to their surface chemistries and cellular uptake pathways. Moreover, both the CDs are pH responsive within a certain pH range, i.e., 4.0-5.4 for ACDs and 6.2-7.2 for LCDs. The ACDs and LCDs are thus successfully applied to visualize the pH fluctuations of the lysosome and endoplasmic reticulum in MCF-7 cells.
细胞器在细胞活动中起着至关重要的作用，细胞器的功能与 pH 值密切相关，因此，靶向细胞器的生物成像及其相关的 pH 传感在生物测定中非常重要。在此，我们报告了用表面调控的碳点（CDs）对特定细胞器（即溶酶体和内质网）进行荧光成像及其 pH 传感。首先通过柠檬酸和尿素的水热处理制备了带有氨基的碳点（ACDs），然后通过与 ACDs 的缩合反应得到了月桂胺功能化的碳点（LCDs）。所制备的 ACDs 和 LCDs 分别为溶酶体和内质网提供了清晰明亮的成像结果。这两种 CD 的亚细胞靶向特征归因于它们的表面化学和细胞摄取途径。此外，这两种 CD 在一定的 pH 范围内均具有 pH 响应性，即 ACDs 的 pH 值范围为 4.0-5.4，LCDs 的 pH 值范围为 6.2-7.2。因此，ACDs 和 LCDs 成功地应用于可视化 MCF-7 细胞中溶酶体和内质网的 pH 波动。
