Acid-Base Responsive Carbon Nanodots Enabling Reversible Write-Erase Fluorescence Switching for Multilevel...

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Stimuli-responsive luminescent materials are crucial for anticounterfeiting and optical encryption.
• Developing stable, rapidly responsive luminescent systems across various conditions is a significant challenge.

Purpose of the Study:

• To synthesize and characterize green-emitting carbon nanodots (G-CDs) with reversible optical switching capabilities.
• To explore the potential of G-CDs in dynamic anticounterfeiting and secure optical encryption applications.

Main Methods:

• Solvothermal synthesis of green-emitting carbon nanodots (G-CDs).
• Photoluminescence spectroscopy to analyze emission properties and pH-dependent switching.
• Incorporation of G-CDs into polymer-based fluorescent inks for anticounterfeiting pattern fabrication.

Main Results:

• Synthesized G-CDs exhibit bright green emission (508 nm) with a 27.10% photoluminescence quantum yield (PLQY).
• G-CDs demonstrate three reversible optical states: nonemissive (acidic), green emission (neutral), and yellow-shifted emission (alkaline).
• Rapid, noncontact optical modulation achieved in both liquid and vapor phases; stable performance across repeated acid-base cycles.

Conclusions:

• G-CDs offer a robust platform for reversible write-erase fluorescence switching.
• The developed G-CDs are suitable for multilevel optical anticounterfeiting and secure information encryption.
• Surface-state engineering of carbon nanodots is key for tunable acid-base switchable luminescence.