Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy
Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy
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利用荧光寿命成像显微镜进行细胞内 pH 传感的碳点
DOI：
10.3390/nano10040604
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发表时间：
2020-04-01
期刊：
影响因子：
5.3
通讯作者：
Mi, Lan
中科院分区：
文献类型：
--
作者：
Huang, Maojia;Liang, Xinyue;Mi, Lan
细胞内pH的监测对于了解细胞内的运输和功能具有重要意义。基于荧光强度或光谱研究的生物传感有各种局限性。在本研究中，首次将pH敏感的碳点(CDs)用于荧光寿命成像显微镜(FLIM)的细胞内pH传感。Flim是一种用于检测微环境的高度敏感的方法，它可以克服基于荧光强度的生物传感方法的局限性。不同pH环境下，硫化镉表面基团不同，导致荧光寿命值不同。在pH为2.6-8.6的范围内，硫化镉水溶液的荧光寿命从1.6 ns逐渐变化到3.7 ns。在pH缓冲液处理的活细胞中也发现了类似的荧光寿命变化。通过测量CDS的荧光寿命，实现了对活细胞中溶酶体、胞浆和细胞核的检测。特别是，相量薄膜分析被用来改善pH成像。此外，为了模拟细胞内复杂的微环境，还考察了辅酶、氨基酸和蛋白质对CDS荧光寿命的影响。
The monitoring of intracellular pH is of great importance for understanding intracellular trafficking and functions. It has various limitations for biosensing based on the fluorescence intensity or spectra study. In this research, pH-sensitive carbon dots (CDs) were employed for intracellular pH sensing with fluorescence lifetime imaging microscopy (FLIM) for the first time. FLIM is a highly sensitive method that is used to detect a microenvironment and it can overcome the limitations of biosensing methods based on fluorescence intensity. The different groups on the CDs surfaces changing with pH environments led to different fluorescence lifetime values. The CDs aqueous solution had a gradual change from 1.6 ns to 3.7 ns in the fluorescence lifetime with a pH range of 2.6–8.6. Similar fluorescence lifetime changes were found in pH buffer-treated living cells. The detection of lysosomes, cytoplasm, and nuclei in living cells was achieved by measuring the fluorescence lifetime of CDs. In particular, a phasor FLIM analysis was used to improve the pH imaging. Moreover, the effects of the coenzymes, amino acids, and proteins on the fluorescence lifetime of CDs were examined in order to mimic the complex microenvironment inside the cells.