Tunable Interparticle Connectivity in Gold Nanosphere Assemblies for Efficient Photoacoustic Conversion

Area of Science:

• Nanotechnology
• Biomedical Imaging
• Materials Science

Background:

• Plasmonic nanostructures are crucial for photoacoustic (PA) imaging.
• Controlling nanostructure assembly is key to optimizing PA signal generation.

Purpose of the Study:

• To investigate the effect of inter-particle connectivity in gold nanosphere (Au NS) assemblies on PA signal generation.
• To enhance PA imaging contrast and photostability using tailored nanostructures.

Main Methods:

• Fabrication of anisotropic Au NS nanoassemblies with modulated diameter and inter-particle spacing.
• Systematic evaluation of PA signal intensity and photostability under varying connectivity conditions.

Main Results:

• Semi-connected Au NS nanoassemblies exhibited 3.4-fold and 2.4-fold higher PA signals than non-connected and fully connected assemblies, respectively.
• Semi-connected assemblies demonstrated high photodamage threshold and excellent photostability above ANSI limits due to reduced atom diffusion.

Conclusions:

• Semi-connected nanostructures offer a promising strategy for high-contrast and reliable PA imaging.
• These nanostructures exhibit superior photostability, surpassing conventional plasmonic contrast agents for advanced PA applications.