Neuroscience X quantum sensing

Hi neuroscience community. I am an editor in the quantum sensing hub. Quantum sensing using quantum effect to detect environmental signals, specifically, I am using nitrogen vacancy quantum defects in diamond to sense external magnetic signal.

A few years ago, there is an interesting publication using this diamond quantum sensor to detect action potential (AP) from a single neuron excised from giant marine worm and squid. The advantages of diamond quantum sensors include: a) biocompabillity: you can put/grow the sample on top of the diamond sensor (the substrate) directly. b) high spatial resolution: because sensor to sample stand-off distance is made very small and c) non-invasive: because the magnetic signal can permeate outside the sample, which is different from electric signal that usually dies off quickly due to Debye screening.

With the above advantages and good sensitivity, the paper demonstrated sensing a) AP propagation direction b) the non-uniform shape of the giant neuron, which causes a change in AP propagation speed and ultimately the magnetic signal amplitude depending on whether AP start from the thicker/thinner end of the neuron

I think the result should have been well documented in neuroscience much much earlier and could have been conventionally studied using electrophysiology. However, the sell points for that paper are a) with continued improvement in magnetic sensitivity, ultimately, resolving AP firing events in a cluster of neurons, non-invasively, is possible, and b) it marked an important initial step in using quantum sensor to perform non-trivial experiments in neuroscience with extremely close sensor-sample proximity.

However, spatially resolving individual neurons within a 2D pattern is still very far away from current technical perspective. Right now, the best performing sensor typically has a volume normalized sensitivity of 30nT/sqrt(Hz)(um)^(3/2), basically, it means if you take 1um^3 volume of such sensor, and you average for 1s, your noise floor would be about 30 nano-Tesla. Of course you can use a larger sensor volume, but that means you have worse spatial resolution. As I am dabbling into neuroscience literature, I want to ask two questions in this community

What are some interesting neuroscience research/challenge you encountered recently, that a diamond quantum sensor may be employed to contribute scientific value? Ideally, there should be magnetic signal (sub or greater than nano-Tesla) and spatial feature should be around or greater than um scale. Links to the articles would be very helpful.
What pre-print website do you use to get the latest neuroscience results?

You comments will be greatly appreciated, and I will award RSC :)

Preprint

Preprint

Neuroscience X quantum sensing