Nanodiamond as a sensor for biologically generated electric and magnetic fields
One of the quiet scientific revolutions of the last 30 years has been in our ability to efficiently create materials with defined properties on demand and to exacting specifications. One such system is artificially grown diamond. This is interesting both for its intrinsic properties (such as extreme hardness, high thermal conductivity and resilience to both chemical and radiation damage) and because, when you dope diamond with other elements, it forms various “defect systems” associated with the presence of non-carbon elements in the diamond lattice. Our research uses the optical properties of one such system in which a nitrogen atom replaces one carbon atom and an additional carbon atom is missing from a neighbouring site. This nitrogen-vacancy (NV) centre is a common defect in diamond. In high densities they give diamond a yellow colour since they are optically active – each defect can emit either red or yellow light depending on whether it is electrically charged or not. It is the charged state that excites me most as it is shows various effects that allow it to be used as a sensor of electric, magnetic and stress fields. Additionally, through the property of the electron known as spin, measurements with the NV centre can be made highly sensitive by taking advantage of recently developed techniques known as quantum-enhanced metrology.
We aim to create “super-resolution” microscopes that use NV centres to measure local magnetic and electric fields with exquisite sensitivity and accuracy. As such, we can envisage viewing the firing of neural cells in real time and with a resolution and field of view that could encompass networks of tens or hundreds of neurons. This will allow the detailed mapping of biological structures and, since we can use adaptive optics techniques to correct for any optical aberrations, these structures can be located in living tissue.
We are part of the Centre for Neural Circuits and Behaviour along with the groups of Gero Miesenböck, Scott Waddell, Martin Booth, Stephen Goodwin, Korneel Hens and Tim Vogels.