Unveiling the Excited-State Dynamics and Interfacial Interactions in Dye-Sensitized NaNdF₄ Nanoparticles for...

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Lanthanide nanoparticles (NPs) have weak absorption, limiting their use in photothermal applications.
• Dye sensitization offers a strategy to enhance NP light absorption and energy transfer.
• Understanding interfacial interactions and excited-state dynamics is crucial for optimizing dye-sensitized NPs.

Purpose of the Study:

• To investigate the coordination and aggregation of cypate dyes on sodium neodymium fluoride (NaNdF4) NPs.
• To elucidate the influence of interfacial interactions on resonant energy transfer.
• To explore the photothermal conversion efficiency and anti-photobleaching properties of these nanocomposites.

Main Methods:

• Steady-state and transient absorption spectroscopy were employed.
• Theoretical calculations were performed to understand dye-NP interactions.
• Photothermal conversion efficiency was measured and compared to existing materials.

Main Results:

• Interfacial interactions significantly influence resonant energy transfer between cypate dyes and NaNdF4 NPs.
• A synergetic heat-generation mechanism involving lanthanide cross-relaxation and dye intermolecular collisions was identified.
• The cypate-NaNdF4 nanocomposites achieved a photothermal conversion efficiency of 50.4%.
• Dye sensitization improved anti-photobleaching ability by inhibiting intersystem crossing.

Conclusions:

• Dye-sensitized NaNdF4 NPs offer a promising platform for efficient photothermal conversion.
• These nanocomposites exhibit enhanced photothermal effects, stability, and NIR-II luminescence.
• The findings highlight the potential of these materials for theranostic applications.