Diamond Magnetic Microscopy of Malarial Hemozoin Nanocrystals
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2019-03-12 |
| Journal | Physical Review Applied |
| Authors | Ilja Fescenko, Abdelghani Laraoui, Janis Smits, Nazanin Mosavian, Pauli Kehayias |
| Institutions | Johannes Gutenberg University Mainz, University of California, Berkeley |
| Citations | 71 |
Abstract
Section titled âAbstractâMagnetic microscopy of malarial hemozoin nanocrystals is performed by optically detected magnetic resonance imaging of near-surface diamond nitrogen-vacancy centers. Hemozoin crystals are extracted from Plasmodium falciparum-infected human blood cells and studied alongside synthetic hemozoin crystals. The stray magnetic fields produced by individual crystals are imaged at room temperature as a function of the applied field up to 350 mT. More than 100 nanocrystals are analyzed, revealing the distribution of their magnetic properties. Most crystals (96%) exhibit a linear dependence of the stray-field magnitude on the applied field, confirming hemozoinâs paramagnetic nature. A volume magnetic susceptibility of 3.4 Ă 10<sup>-4</sup> is inferred with use of a magnetostatic model informed by correlated scanning-electron-microscopy measurements of crystal dimensions. A small fraction of nanoparticles (4/82 for Plasmodium falciparum-produced nanoparticles and 1/41 for synthetic nanoparticles) exhibit a saturation behavior consistent with superparamagnetism. Translation of this platform to the study of living Plasmodium-infected cells may shed new light on hemozoin formation dynamics and their interaction with antimalarial drugs.