Hidden imaging in thin polymer films with embedded fluorescent peptide nanodots

Area of Science:

• Biophotonics
• Nanotechnology
• Materials Science

Background:

• Fluorescent nanostructures are crucial for high-resolution hidden imaging, tracking, labeling, and anti-counterfeiting applications.
• Existing nanostructures include quantum dots, carbon dots, organic dyes, lanthanide nanocrystals, and DNA.
• There is a need for novel, biocompatible fluorescent nanostructures with tunable properties and unique functionalities.

Purpose of the Study:

• To introduce novel fluorescent (FL) encoding nanostructures based on peptide dots.
• To investigate the photophysical properties of these peptide dots, including their fluorescence and photo-bleaching behavior.
• To demonstrate a new approach for high-resolution, long-term optical memory using these peptide dots.

Main Methods:

• Synthesis and characterization of nanometer-scale peptide dots.
• Refolding peptides into beta-sheet secondary structures to induce fluorescence.
• Measurement of fluorescence quantum yield and spectral coverage.
• Investigation of irreversible photo-bleaching effects.
• Fabrication of thin polyvinyl alcohol (PVA) polymer films embedded with peptide nanodots for optical memory demonstration.

Main Results:

• Peptide dots exhibit strong and tunable fluorescence across the visible spectrum.
• The peptide dots function as next-generation nanoscale light sources with a 30% quantum yield.
• A significant irreversible photo-bleaching effect was observed, linked to the destruction of hydrogen bonds in the beta-sheet structure.
• Demonstrated high-resolution optical memory by recording photo-bleached patterns, barcodes, and images in PVA films.

Conclusions:

• Peptide dots represent a new class of fluorescent nanostructures with promising biophotonic properties.
• The tunable fluorescence and irreversible photo-bleaching make them suitable for advanced imaging and secure data storage.
• This technology offers a novel pathway for creating high-resolution, long-term optical memory devices.