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Carbon Dots for Intracellular pH Sensing with Fluorescence Lifetime Imaging Microscopy
Maojia Huang1, Xinyue Liang1, Zixiao Zhang1
1Department of Optical Science and Engineering, Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing, Green Photoelectron Platform, Fudan University, Shanghai 200433, China.
Nanomaterials (Basel, Switzerland)
|March 29, 2020
Summary
This study introduces pH-sensitive carbon dots (CDs) for intracellular pH sensing using fluorescence lifetime imaging microscopy (FLIM). This novel approach overcomes limitations of traditional methods, enabling precise monitoring of cellular environments.
Area of Science:
- Biomedical Engineering
- Nanotechnology
- Cell Biology
Background:
- Intracellular pH monitoring is crucial for understanding cellular processes.
- Existing fluorescence-based biosensing methods have limitations in sensitivity and accuracy.
- Need for advanced techniques to accurately measure pH in complex cellular microenvironments.
Purpose of the Study:
- To develop a novel method for intracellular pH sensing using pH-sensitive carbon dots (CDs).
- To utilize fluorescence lifetime imaging microscopy (FLIM) for enhanced sensitivity and accuracy in pH measurements.
- To demonstrate the application of this technique in living cells, including specific organelle detection.
Main Methods:
- Synthesis and characterization of pH-sensitive carbon dots (CDs).
- Application of fluorescence lifetime imaging microscopy (FLIM) for measuring fluorescence lifetime changes.
- Utilized phasor FLIM analysis for improved pH imaging in living cells.
- Investigated the influence of cellular components (coenzymes, amino acids, proteins) on CD fluorescence lifetime.
Main Results:
- CDs exhibited a significant change in fluorescence lifetime (1.6 ns to 3.7 ns) across a pH range of 2.6-8.6.
- Similar pH-dependent fluorescence lifetime variations were observed in living cells.
- Successful detection and imaging of lysosomes, cytoplasm, and nuclei using FLIM with CDs.
- Phasor FLIM analysis enhanced the spatial resolution and accuracy of pH imaging.
Conclusions:
- pH-sensitive CDs combined with FLIM offer a sensitive and robust platform for intracellular pH sensing.
- This technique overcomes the limitations of intensity-based fluorescence methods.
- The study demonstrates the potential of CDs-FLIM for real-time monitoring of cellular pH dynamics in complex biological systems.
