Imaging the Magnetization of Single Magnetite Nanoparticle Clusters via Photothermal Circular Dichroism

• DOI: 10.1021/acs.nanolett.2c00178
• Publication Date: 2022-04-14T19:16:00Z
• Authors: Patrick Spaeth; Subhasis Adhikari; Kaveh Lahabi; Martin Dieter Baaske; Yonghui Wang; Michel Orrit
• Keywords: Superparamagnetism

Magnetic imaging is a versatile tool in biological and condensed-matter physics. Existing magnetic techniques either require demanding experimental conditions which restrict the range of their applications or lack spatial resolution required for single-particle measurements. Here, we combine photothermal (PT) microscopy with circular dichroism (MCD) to develop technique using visible light. Unlike most techniques, (PT MCD) works particularly well single nanoparticles immersed liquids. As proof principle, demonstrate CD superparamagnetic magnetite nanoparticulate clusters microscope immersion oil. The sensitivity our method allowed us probe magnetization curve ∼400-nm-diameter clusters.