Covalent organic framework-based fluorescent nanoprobe for intracellular pH sensing and imaging

Area of Science:

• Biochemistry
• Materials Science
• Cell Biology

Background:

• Lysosomes are vital acidic organelles involved in cellular degradation.
• Lysosomal pH disturbances are linked to dysfunction and disease.
• Accurate intracellular pH monitoring is crucial for disease research.

Purpose of the Study:

• To develop a novel pH-responsive fluorescent probe for lysosomal pH imaging.
• To investigate the potential of covalent organic frameworks (COFs) for biological sensing.
• To establish a tool for in situ monitoring of lysosomal pH fluctuations.

Main Methods:

• Synthesis of a methoxy-based covalent organic framework (TAPB-DMTP-COF).
• Characterization of the COF's structure, toxicity, and pH responsiveness.
• Utilizing confocal fluorescence imaging for lysosomal pH monitoring in cells.

Main Results:

• The TAPB-DMTP-COF exhibited a regular crystal structure, low toxicity, and good pH responsiveness.
• The probe demonstrated pH-dependent fluorescence with good linearity in aqueous solutions.
• Effective in situ monitoring of lysosomal pH changes (pH 4.0–7.4) was achieved.

Conclusions:

• The developed TAPB-DMTP-COF serves as a selective and effective probe for lysosomal pH imaging.
• This probe offers a new approach for intracellular pH sensing and studying lysosome-related diseases.
• The findings contribute to understanding disease mechanisms linked to abnormal lysosomal pH.