Towards the smallest nanodiamond quantum sensor

Branco Weiss Fellow Takuya Segawa and co-workers have successfully demonstrated important steps towards smaller than ever quantum sensors in the form of diamond nanocrystals.

A crystal defect in diamond, the nitrogen-vacancy center, has fluorescent and magnetic properties, which can be used to measure temperature, magnetic or electric fields in its nanoscale environment. The challenge is to engineer the smallest possible nanodiamond, which still contains a single fluorescent defect.

Dr. Segawa and his team have shown for the first time that the number of nitrogen-vacancy centers can be increased by electron irradiation in nanodiamonds as small as 5 nanometers. The smallest nanodiamond currently used for biological applications is about 30 nanometers in size. This is much larger than the usual size of biomolecules. By reducing the size of fluorescent nanodiamonds to 5 nanometers, the dimensions become comparable to the green fluorescent protein (GFP), a popular fluorescent label for biomolecules. By using these fluorescent nanodiamonds, various measurements inside living cells become possible.

Read the paper published in ACS Nano

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