Quantitative Ratiometric Biosensors Based on Fluorescent Ferrocene-Modified Histidine Dipeptide Nanoassemblies

Area of Science:

• Biomaterials Science
• Chemical Biology
• Nanotechnology

Background:

• Fluorescent proteins (FPs) are crucial for quantitative assessment of internalized biomolecules.
• Peptide nanostructures are preferred for fluorescent soft matter synthesis but rarely exhibit multicolor emission.
• Achieving ratiometric emission from a single peptide fluorophore remains a significant challenge.

Purpose of the Study:

• To develop a bioinspired peptidyl platform for ratiometric intracellular quantitation.
• To create a single peptide fluorophore capable of multicolor emission.
• To enable quantitative understanding of biomolecule trafficking and subcellular fate.

Main Methods:

• Synthesis of a single ferrocene-modified histidine dipeptide.
• Investigation of ratiometric fluorescence properties.
• Exploration of assembly-induced emission mechanisms (hydrogen bonds, aromatic interactions).

Main Results:

• A linear correlation was established between the green-to-blue fluorescence ratio and peptide concentration over three orders of magnitude.
• The ratiometric fluorescence was demonstrated to be an assembly-induced emission phenomenon.
• A modular design approach was validated for constructing intricate peptides with retained ratiometric properties.

Conclusions:

• The developed peptidyl platform enables ratiometric intracellular quantitation using a single peptide fluorophore.
• This technique offers a flexible and generalizable approach for designing stoichiometric biosensors.
• The findings advance the quantitative analysis of biomolecule trafficking and subcellular dynamics.