Single-Particle Photothermal Circular Dichroism and Photothermal Magnetic Circular Dichroism Microscopy

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Chirality and magnetism are fundamental properties with significant implications across various scientific disciplines.
• Existing techniques for studying these properties at the nanoscale often face limitations in sensitivity and specificity.

Purpose of the Study:

• To highlight recent advancements in single-particle photothermal circular dichroism (PT CD) and photothermal magnetic circular dichroism (PT MCD) microscopy.
• To underscore the potential of these techniques for probing chirality and magnetism at the single-particle level.

Main Methods:

• Photothermal circular dichroism (PT CD) microscopy measures differential absorption of circularly polarized light by chiral nanoobjects, yielding pure circular dichroism signals.
• Photothermal magnetic circular dichroism (PT MCD) microscopy utilizes the polar magneto-optical Kerr effect to optically probe magnetic properties of nanoparticles as small as 20 nm.

Main Results:

• PT CD provides pure circular dichroism signals, free from birefringence and linear dichroism contributions.
• PT MCD enables optical investigation of magnetic properties in single nanoparticles, revealing nanoscale magnetic heterogeneity.
• Both PT CD and PT MCD have demonstrated utility in chiral plasmonics and magnetic nanomaterials.

Conclusions:

• Single-particle PT CD and PT MCD microscopy represent significant breakthroughs in nanoscale characterization.
• These techniques open new avenues for research in biology, nanomaterial science, chiral plasmonics, and magnetic materials.