Development of a platform for sensing cellular electrical activity using nitrogen vacancy centers in nanodiamonds

Abstract

The nitrogen vacancy center (NV) in diamond hosts unique optical properties that allows it to be used for sensing magnetic fields, electric fields, and temperature. In addition, the photostability of the NV center and the biocompatibility of diamond suggests the utility of the NV center for biosensing. The dependence of the charge state of the NV center on the local electrochemical environment suggests that the NV center could be used as an optical sensor for electrophysiology. In this thesis, a platform to evaluate the utility of the NV center for voltage sensing is established. First, an electrophysiology setup is built and characterized on HEK293 cells. The setup adds functionality to a home built microscope so that cells can be electrically controlled while simultaneously observing the fluorescence. Second, the staining of neurons with hydrogen-terminated nanodiamonds (NDs) with NV centers is improved. Together, the improved staining of neurons with nanodiamonds along with using the electrophysiology setup to observe modulation forms a platform for future study of the NV center as a voltage sensor.