Final Report Summary - NEURONQ (Quantum magnetic sensing of neurons using nitrogen-vacancy centers in diamond) Brain research and quantum technology are at the focus of 21st century science. Although theoretical and experimental studies have provided some insights regarding the mechanisms with which the brain acquires, represents and stores information, a comprehensive theory of the brain and the underlying neural information processing is still missing. Experimental techniques to study brain processes at different levels of description are therefore of fundamental importance for brain research. The NeuronQ project aims towards the development of an ultrasensitive quantum-sensor for real-time recording of neural activity on the sub-neuron, single neuron and network level using nitrogen-vacancy centers in diamond. The nitrogen-vacancy defect (or NV center) in the crystal structure of the diamond is a unique "atom-like" system with quantum properties including sharp optical and microwave transitions, Zeeman sublevels and the ability to undergo optical pumping. The spin states of the NV center, which can be readout optically using electron spin resonances, can interact with neural magnetic and electric fields, thus, providing the underlying principle for an NV center based neuroimaging device with unprecedented spatiotemporal resolution.In the first stage of the NeuronQ project we have assembled the main building blocks for this technology and we have investigated different sensing protocols using nanofabricated chips with micro-electrode arrays to simulate neural magnetic and electric field conditions. The experimental studies have been accompanied by theoretical modeling and computer simulation to estimate the effect of the interaction of a NV center based quantum sensor with neural excitations. In parallel, experiments of neural cell culture growths on bulk diamonds and delivery of nanodiamonds to neural tissue - prerequisites for developing a functional bio-sensor - have been performed. Together with our European partners we are now considering how to progress to the next level and put together the first functioning models of a new device.A NV center based neural sensor will presumably have significant impact on basic neuroscience research and the understanding of neurological disorders as well as lead to new neurotechnology, such as novel screening methods for neuropharmaceutical drug development, brain-machine interfaces and low-cost MEG-like brain imaging devices.
