Non-Aromatic Fluorescence in Biological Matter: The Exception or the Rule?

Area of Science:

• Biophysics
• Materials Science
• Biochemistry

Background:

• Traditionally, fluorescence in biological matter is linked to aromatic or conjugated groups.
• Peptides implicated in neurodegenerative diseases (Alzheimer's, Parkinson's, Huntington's) exhibit intrinsic visible fluorescence, even without aromatic residues.
• This discovery challenges conventional understanding and sparks interest in novel biophotonic materials.

Purpose of the Study:

• To review the current understanding of intrinsic fluorescence in non-aromatic peptides.
• To explore the mechanism of fluorescence generation through supramolecular assembly.
• To identify open questions and future research directions in non-aromatic fluorescence.

Main Methods:

• This perspective synthesizes existing experimental and theoretical findings.
• It reviews the proposed mechanism involving electronic interactions in supramolecular assemblies.
• It highlights key challenges and unanswered questions in the field.

Main Results:

• A growing consensus attributes this fluorescence to electronic interactions within supramolecular assemblies of non-optically active molecules.
• The phenomenon is observed in peptides associated with neurodegenerative diseases.
• Despite progress, many aspects remain poorly understood.

Conclusions:

• Non-aromatic fluorescence in peptides is a significant emerging area with potential applications in biophotonics.
• Further experimental and theoretical research is needed to fully elucidate the underlying mechanisms.
• Understanding this phenomenon could lead to new diagnostic tools and therapeutic strategies for neurodegenerative diseases.