I'd note that the same group headed by Lutz achieved single electron ESR with a similar scanning methodology at least 15 years back so this was follow on work. It's still amazing and incredibly difficult... just imagine how you would produce something (a test sample) that you know will have only 1 magnetically resonant atom in the affected scan area!
At the time the hope was to use single atom NMR to image DNA, but I think that has largely been accomplished by other methods.
edit: The paper in Nature for those with access. https://www.nature.com/articles/s41567-019-0573-x
Can I ask about the rationale motivating attempts to image DNA specifically - was it mainly that we were attempting to get better spacial understanding of the different molecular conformations it enters at different stages of the cellular cycle?
Or imaging DNA transcription? Or DNA polymerase in action?
or was imaging DNA this way an attractive goal because we already anticipated some particular applications?
* Hand drill: https://youtu.be/FmmNRaKpBTI?t=1812
* Bridgeport mill: https://youtu.be/FmmNRaKpBTI?t=1852
This is like a physical manifestation of what we come up with during an all-night Hackathon.