Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing

详细信息    查看全文

• 作者：Jingfang Shangguan ; Dinggeng He ; Xiaoxiao He ; Kemin Wang ; Fengzhou Xu ; Jinquan Liu ; Jinlu Tang ; Xue Yang ; Jin Huang
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：August 2, 2016
• 年：2016
• 卷：88
• 期：15
• 页码：7837-7843
• 全文大小：472K
• 年卷期：0
• ISSN：1520-6882

文摘

Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I_475 nm/I_545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I_475 nm/I_545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels.