Anisotropic gold nanoparticles: synthesis, properties, applications, and toxicity

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Anisotropic gold nanoparticles (AuNPs) have garnered significant scientific interest for over a century.
• Research has accelerated since 2000, with advancements in synthesizing diverse 1D, 2D, and 3D shapes, including hollow structures and nanoshells.

Purpose of the Study:

• To review the historical development, synthetic methods, and diverse shapes of anisotropic AuNPs.
• To summarize the critical applications of these nanomaterials in optical, biomedical, and catalytic fields.
• To address the emerging concerns regarding the toxicity of anisotropic AuNPs.

Main Methods:

• Review of existing literature on anisotropic gold nanoparticle synthesis and characterization.
• Analysis of plasmon absorption properties, particularly in the near-infrared (NIR) region.
• Compilation of data on applications in theranostics, optical devices, and catalysis.

Main Results:

• Anisotropic AuNPs exhibit plasmon absorption in visible and NIR regions, tunable by shape and medium.
• NIR absorption can be optimized for minimal absorption by living tissues, crucial for medical applications.
• Au nanowires (AuNWs) function as effective plasmon waveguides for optical devices.

Conclusions:

• The unique optical properties of anisotropic AuNPs, especially their tunable NIR absorption, drive significant applications in theranostics and advanced optical devices.
• The rapid expansion of anisotropic AuNP applications across optical, biomedical, and catalytic domains highlights their versatility.
• Further research into synthesis, applications, and toxicity is essential for this rapidly evolving class of nanomaterials.