Defect Damping-Enhanced Plasmonic Photothermal Conversion

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Enhancing photothermal conversion efficiency in plasmonic nanostructured particles (PNPs) is crucial for thermoplasmonics applications.
• Achieving high efficiency is challenging for PNPs with specific morphology and composition requirements.

Purpose of the Study:

• To present a novel strategy for intrinsically enhancing photothermal conversion in PNPs.
• To investigate the effect of defect-induced damping on PNP photothermal performance.

Main Methods:

• Developed a theoretical model of a defect-damped harmonic oscillator to correlate PNP structure with photothermal conversion.
• Fabricated defect-enriched gold nanostars (Au NSs) with sizes around 100-150 nm.
• Conducted in vitro and in vivo experiments to validate enhanced photothermal performance.

Main Results:

• Theoretical analysis showed defect-induced damping suppresses light scattering and improves photothermal conversion efficiency, particularly for larger PNPs (>100 nm).
• Experimentally, defect-enriched Au NSs exhibited significantly higher photothermal performance, with a 23% increase in conversion efficiency compared to defect-poor counterparts.
• In vitro and in vivo studies confirmed superior photothermal efficacy of defect-enriched PNPs in cells and mouse tumors.

Conclusions:

• Defect-induced damping offers an intrinsic strategy to significantly enhance the photothermal conversion of sufficiently large PNPs.
• This approach is adaptable for PNPs with specific application-driven morphologies and compositions.
• The strategy can be combined with existing methods to further boost photothermal performance.