Water-soluble Hantzsch ester as switch-on fluorescent probe for efficiently detecting nitric oxide

Area of Science:

• Chemical Biology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Nitric oxide (NO) is a crucial signaling molecule in biological systems.
• Development of sensitive and selective fluorescent probes for NO detection is essential for biological research.

Purpose of the Study:

• To synthesize and characterize a water-soluble Hantzsch ester derivative of coumarin (DHPS) for fluorescent sensing of NO.
• To investigate the sensing mechanism and evaluate the probe's performance in aqueous solutions and biological cells.

Main Methods:

• Synthesis and spectral characterization of DHPS.
• Fluorescence spectroscopy to assess probe response to NO.
• Detection limit determination.
• Cytotoxicity assays.
• Cellular imaging of endogenous NO production.

Main Results:

• DHPS exhibits weak fluorescence that is significantly enhanced upon reaction with NO.
• The probe demonstrates high selectivity and sensitivity for NO with a detection limit of 18 nM.
• The NO-induced aromatization of DHPS to PYS is identified as the fluorescence switching mechanism.
• DHPS and PYS show good biocompatibility.
• DHPS successfully tracks endogenous NO production in RAW 264.7 cells.

Conclusions:

• DHPS is a highly effective fluorescent probe for NO detection in aqueous media.
• The probe's mechanism involves a clear fluorescence turn-on response.
• DHPS is suitable for monitoring NO in living cells, demonstrating its potential in biological and medical applications.