A fluorescent probe for bisulfite ions: its application to two-photon tissue imaging

Area of Science:

• Chemical Sensors
• Fluorescent Probes
• Analytical Chemistry

Background:

• Bisulfite ions play crucial roles in biological processes.
• Accurate detection of bisulfite ions is essential for biological and environmental monitoring.
• Existing detection methods often lack specificity or sensitivity.

Purpose of the Study:

• To develop a benzoxazinone-based fluorescent probe for specific and efficient bisulfite ion detection.
• To evaluate the probe's performance in aqueous media and biological systems.
• To enable imaging of endogenous bisulfite ions in cells and tissues.

Main Methods:

• Synthesis of a benzoxazinone-based fluorescent probe.
• Characterization of the probe's spectral properties and response to bisulfite ions.
• Assessment of probe selectivity against potential interfering species.
• Evaluation of probe performance in cellular and in vivo imaging using two-photon microscopy.

Main Results:

• The probe exhibited a specific turn-on fluorescence response in the red wavelength region upon reaction with bisulfite ions.
• High selectivity was observed, with no interference from common anions, amino acids, or thiols.
• The probe demonstrated a fast response time, low detection limit, and good cell membrane permeability.
• Successful imaging of endogenous bisulfite ions in HeLa cells and deep tissues of mice was achieved due to its two-photon excitability.

Conclusions:

• The developed benzoxazinone probe is a highly specific and sensitive tool for bisulfite ion detection.
• The probe's properties make it suitable for real-time monitoring of bisulfite ions in complex biological samples.
• This fluorescent probe opens new avenues for studying the biological functions of bisulfite ions.