New Benzimidazole-Based pH-Sensitive Fluorescent Probes

Area of Science:

• Organic Chemistry
• Materials Science
• Biotechnology

Background:

• Benzimidazole derivatives are explored for novel optical properties.
• pH-sensitive fluorescent probes are crucial for biological and chemical sensing.
• Bacterial biofilms present challenges in diagnostics and treatment.

Purpose of the Study:

• Synthesize and characterize novel benzimidazole compounds with a propylsulfonate moiety.
• Investigate the pH-dependent optical and photoluminescent properties of these compounds.
• Evaluate their potential as fluorescent probes for bacterial biofilm imaging and toxicity.

Main Methods:

• Synthesis via condensation reactions.
• Structural confirmation using NMR, FT-IR, and HRMS.
• Spectroscopic analysis (absorption, photoluminescence) across a pH range.
• Toxicity assessment using bacterial sensors.
• Bioimaging of bacterial biofilms with multiphoton microscopy.

Main Results:

• Successfully synthesized and characterized new benzimidazole derivatives.
• Compounds exhibit pH-sensitive optical properties, with derivative 3c showing a prominent response from pH ~4.5.
• Demonstrated potential as fluorescent probes for bacterial biofilms, with differential staining of extracellular matrix and cells based on incubation time.
• Dye 3c can be excited at 458 nm or 750 nm for multiphoton imaging.

Conclusions:

• The synthesized benzimidazole compounds are effective pH-sensitive fluorescent probes.
• Derivative 3c is a promising candidate for imaging bacterial biofilms in a biologically relevant pH range.
• The compounds show potential for diagnostic applications in microbiology and materials science.