A novel acidic pH fluorescent probe based on a benzothiazole derivative

Area of Science:

• Chemical Sensing
• Molecular Probes
• Biophysical Chemistry

Background:

• Accurate monitoring of acidic pH is vital in biological systems.
• Existing probes may lack selectivity or rapid response in acidic environments.
• Benzothiazole derivatives offer potential for developing novel fluorescent sensors.

Purpose of the Study:

• To design, synthesize, and evaluate a novel fluorescent probe for acidic pH detection.
• To investigate the sensing mechanism and performance characteristics of the probe.
• To assess the probe's applicability in biological imaging.

Main Methods:

• Synthesis of a benzothiazole-based fluorescent probe.
• Spectroscopic analysis to determine linear response range and pKa value.
• Evaluation of selectivity against interfering species.
• Confocal fluorescence imaging in live HeLa cells.

Main Results:

• The probe exhibits a linear response in the acidic pH range (3.44–6.46) with a pKa of 4.23.
• Fluorescence enhancement is attributed to the hindrance of photo-induced electron transfer (PET).
• The probe demonstrates high selectivity for H+ and a rapid response time (<1 min).
• Successful application in live cell imaging, selectively staining lysosomes.

Conclusions:

• The developed fluorescent probe is a sensitive and selective tool for monitoring acidic pH.
• Its properties make it suitable for real-time pH measurements in biological research.
• The probe enables specific lysosomal staining in live cells, aiding cellular studies.