Plasmonic rod-in-shell nanoparticles for photothermal therapy

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Optical Physics

Background:

• Plasmonic gold nanoparticles are explored for photothermal therapy (PTT).
• Current research focuses on the first near-infrared (NIR) window (650-950 nm).
• Limited studies investigate nanoparticles for the second NIR window (1000-1350 nm) for deeper tissue penetration.

Purpose of the Study:

• To numerically explore the optical absorption properties of rod-in-shell (RIS) nanoparticles.
• To investigate the effect of tuning dimensional parameters (core length, gap size, shell thickness) on RIS particle optical properties.
• To evaluate the potential of RIS nanoparticles for enhanced photothermal therapy in both NIR windows.

Main Methods:

• Extensive numerical simulations of optical absorption.
• Systematic variation of RIS nanoparticle dimensions: core length, gap size, and shell thickness.
• Analysis of absorption cross-section and optical response in the first and second NIR windows.

Main Results:

• RIS nanoparticles exhibit strong, tunable optical absorption in the second NIR window with sizes under 100 nm.
• RIS nanoparticles demonstrate larger absorption cross-sections than nanorods of equivalent gold mass in both NIR windows.
• Orientation-insensitive light absorption in the first NIR window due to mode overlap.

Conclusions:

• RIS nanoparticles possess favorable optical properties for improved photothermal therapy.
• Their tunable absorption in the second NIR window allows for deeper tissue penetration.
• RIS nanoparticles are promising candidates for PTT applications in both the first and second NIR windows.