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NIR-II pH Sensor with a FRET Adjustable Transition Point for In Situ Dynamic Tumor Microenvironment Visualization
Mengyao Zhao1, Jianbo Wang1,2, Zuhai Lei1
1Department of Chemistry, State Key Laboratory of Molecular Engineering of Polymers and iChem, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai, 200433, China.
Angewandte Chemie (International Ed. in English)
|December 10, 2020
Summary
New pH sensors offer sensitive tumor monitoring across a wider range. These tunable sensors enable dynamic visualization of pH changes in vivo using near-infrared imaging.
Area of Science:
- Biomedical Engineering
- Chemical Sensing
- Optical Imaging
Background:
- Tumor microenvironment pH monitoring is crucial for understanding cancer physiology.
- Existing pH sensors have limited detection ranges, hindering comprehensive analysis.
- Sensitive detection is often confined to a narrow pH transition point (pHt).
Purpose of the Study:
- To develop novel pH sensors with adjustable pH transition points (pTAS) for enhanced tumor pH monitoring.
- To achieve sensitive pH detection over a wider physiological range.
- To enable dynamic in vivo visualization of tumor pH fluctuations.
Main Methods:
- Fabrication of serial pH-adjustable sensors (pTAS) by tuning the ratio of aza-BODIPY (NAB) donor and rhodamine-based pre-acceptor (NRh).
- Utilizing Förster resonance energy transfer (FRET) system for pH-sensitive fluorescence.
- Employing dual-channel ratiometric bioimaging in the second near-infrared (NIR-II) window for in vivo studies.
Main Results:
- Achieved a twofold widened pH detection range (6.11-7.22) compared to conventional sensors (6.38-6.94).
- Demonstrated dynamic visualization of in vivo tumor pH increases and decreases.
- Obtained high accuracy with a coefficient of variation under 1% compared to standard pH meters.
Conclusions:
- The developed pTAS provide a sensitive and broadly tunable platform for tumor pH monitoring.
- Adjustable pH transition points significantly enhance the detection range for physiological pH variations.
- NIR-II ratiometric bioimaging with pTAS enables precise, dynamic in vivo tumor pH mapping.
