Southwest Quantum Information and Technology

Diamond magnetic imaging of single paramagnetic biocrystals

Presenting Author: Ilja Fescenko, University of New Mexico CHTM
Contributing Author(s): Abdelghani Laraoui, Janis Smits, Nazanin Mosavian, Pauli Kehayias, Jong Seto, Lykourgos Bougas, Andrey Jarmola, Victor Acosta

Quantum sensors based on diamond nitrogen-vacancy (NV) centers have emerged as a powerful platform for detecting nanomagnetism in biological samples. With this technique, magnetic images of individual nanoparticles exhibiting ferromagnetism and super-paramagnetism have been recorded, but observation of paramagnetic nanoparticles has remained a challenge, owing to their weaker signatures. Of particular interest are paramagnetic hemozoin nanocrystals, which are a byproduct of the breakdown of hemoglobin by malaria parasites. The prevention of hemozoin formation is a primary target of antimalarial drugs, but the molecular mechanism for hemozoin formation is poorly understood. We have performed magnetic imaging of individual hemozoin nanocrystals using optically detected magnetic resonance of a near-surface layer of NV centers on a diamond chip. We measured the magnetic properties of individual hemozoin crystals and unambiguously confirmed their paramagnetic nature. We compared numerous individual natural and synthetically-produced hemozoin nanocrystals and observed heterogeneity in their paramagnetic properties. The results are in good agreement with a magnetostatic model informed by independent measurements of nanocrystal morphology and chemical composition. The translation of this tool to the study of living malarial cell cultures could shed new light on the formation dynamics of hemozoin and their interaction with antimalarial drugs.

(Session 5 : Thursday from 5:00pm - 7:00 pm)