Abdelghani Laraoui1,Rupak Timalsina1,Cody Schultz1,Suvechhya Lamichhane1,Adam Erickson1,Sy-Hwang Liou1,Rebecca Lai1
University of Nebraska-Lincoln1
Abdelghani Laraoui1,Rupak Timalsina1,Cody Schultz1,Suvechhya Lamichhane1,Adam Erickson1,Sy-Hwang Liou1,Rebecca Lai1
University of Nebraska-Lincoln1
Iron is an essential yet toxic redox active element that is found in many cells, including neurons and glial cells. Although substantial efforts have been devoted to understanding the mechanisms behind the abnormal iron accumulation in the diseased neurons and cells [1,2]. Different technqiues, including scanning proton induced X-ray emission spectrometry, have been used to quantify iron in neurons and glial cells [3]; however, most are incapable of high spatial resolution imaging inside a single cell. Diamond quantum sensors based on nitrogen vacancy (NV) centers have emerged as a powerful tool for detecting magnetic signal in iron-containing biological samples with a good combination of spatial resolution and sensitivity [4,5]. Cytochrome C (Cyt. C) is iron-containing biomolecule that plays an important role in the electron transport chain of mitochondria and it is in the Fe(III) paramagnetic state under ambient conditions. We report measurements of Cyt C under different concentrations and locations of the 10-nm NV doped diamond chip. We show a reduction of the NV relaxation time T<sub>1</sub> from few milliseconds to hundreds of microseconds, explained by the spin noise from the intracellular iron spins. We then discuss plans of imaging Cyt C and other iron-containing biomolecules and cells on nanostructured diamond chip integrated with dielectric gratings. [1] S. Oshiro, Adv. in Pharm. Sci. 378278 (2011). [2] R. Ward, et <i>al</i>., The Lancet. Neur. 13(10), 1045 (2014). [3] A. Reinert, et <i>al</i>., 20(1), 25 (2019). [4] P. Wang, et <i>al</i>., Sci. Adv. 5(4), eaau8038 (2019). [5] I. Fescenko, A. Laraoui, et <i>al</i>., Phy. Rev. App. 11(3), 034029 (2019).<br/>Acknowledgment: This material is based upon work supported by the National Science Foundation/EPSCoR RII Track-1: Emergent Quantum Materials and Technologies (EQUATE), Award OIA-2044049. The research was performed in part in the Nebraska Nanoscale Facility: National Nanotechnology Coordinated Infrastructure and the Nebraska Center for Materials and Nanoscience (and/or NERCF), which are supported by the National Science Foundation under Award ECCS: 2025298, and the Nebraska Research Initiative.