A "reactive" turn-on fluorescence probe for hypochlorous acid and its bioimaging application

Area of Science:

• Chemical sensing
• Fluorescent probes
• Biomedical applications

Background:

• Hypochlorous acid (HOCl) is a reactive oxygen species involved in physiological processes and inflammation.
• Specific and sensitive detection of HOCl in biological environments remains challenging.

Purpose of the Study:

• To develop a novel fluorescent probe for the specific detection of hypochlorous acid.
• To investigate the probe's mechanism of action, biocompatibility, and application in living cells.

Main Methods:

• Synthesis and characterization of the aza-BODIPY-CNOH probe.
• Spectroscopic analysis (NMR, HRMS) to confirm the fluorescence mechanism.
• Cell viability assays (MTT) to assess biocompatibility.
• Fluorescence imaging of living RAW264.7 cells.

Main Results:

• The aza-BODIPY-CNOH probe exhibited a turn-on red fluorescence response upon reaction with HOCl.
• Fluorescence was attributed to the oxidation of the aldoxime group to a nitrile oxide.
• The probe demonstrated good biocompatibility and low cytotoxicity.
• Intracellular bright-red fluorescence was observed in cells treated with HOCl, indicating effective sensing.

Conclusions:

• The aza-BODIPY-CNOH probe is a promising tool for the specific detection of hypochlorous acid.
• Its biocompatibility and cell permeability support its application in biological sensing.
• The probe facilitates visualization of HOCl in living cells, aiding in understanding its biological roles.