Vancomycin-lnduced fluorescence and morphological changes in bis(dipeptide)-containing biphenyl supramolecules

Area of Science:

• Supramolecular Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Self-assembling materials offer unique properties for sensing applications.
• Fluorescent probes are valuable tools for detecting biologically relevant molecules.
• The D-Ala-D-Ala moiety is a key component in bacterial cell wall synthesis and a target for antibiotics like vancomycin.

Purpose of the Study:

• To develop a novel self-assembling fluorescent material for the detection of vancomycin.
• To investigate the mechanism of vancomycin-induced changes in the material's morphology and fluorescence.
• To evaluate the specificity and sensitivity of the developed detection system.

Main Methods:

• Synthesis of a biphenyl derivative with D-Ala-D-Ala moieties.
• Induction of self-assembly into nano/microfibers in aqueous EtOH.
• Monitoring morphological and fluorescence changes upon incubation with vancomycin and other proteins.
• Assessing the effect of Ac-Lys(Ac)-D-Ala-D-Ala on fiber regeneration.
• Comparison with a control derivative containing L-Ala-L-Ala.

Main Results:

• The D-Ala-D-Ala derivative self-assembled into fluorescent nano/microfibers.
• Vancomycin induced fiber disappearance and significant fluorescence quenching.
• A detection limit of approximately 57 μM for vancomycin was established.
• Fiber regeneration was achieved using Ac-Lys(Ac)-D-Ala-D-Ala.
• No changes were observed with other proteins or with the L-Ala-L-Ala derivative.

Conclusions:

• The developed D-Ala-D-Ala based fluorescent fibers serve as a sensitive and specific sensor for vancomycin.
• The observed vancomycin-induced phase transition and fluorescence change are unique to the D-Ala-D-Ala moiety.
• This system demonstrates potential for developing new diagnostic tools for vancomycin detection.