Detection of atomic spin labels in a lipid bi-layer using a single-spin nanodiamond probe

TL;DR

This study demonstrates the use of a single-spin nanodiamond sensor to detect individual gadolinium spin labels in a lipid bilayer, enabling real-time nanoscale biological measurements under ambient conditions.

Contribution

It introduces a novel method for detecting atomic-scale spins in biological environments using a single nanodiamond sensor, advancing nanoscale bio-imaging capabilities.

Findings

Detection of gadolinium spin labels in lipid bilayers.

Sensitive measurement of spin relaxation times.

Potential for real-time biological process monitoring.

Abstract

Magnetic field fluctuations arising from fundamental spins are ubiquitous in nanoscale biology, and are a rich source of information about the processes that generate them. However, the ability to detect the few spins involved without averaging over large ensembles has remained elusive. Here we demonstrate the detection of gadolinium spin labels in an artificial cell membrane under ambient conditions using a single-spin nanodiamond sensor. Changes in the spin relaxation time of the sensor located in the lipid bilayer were optically detected and found to be sensitive to near-individual proximal gadolinium atomic labels. The detection of such small numbers of spins in a model biological setting, with projected detection times of one second, opens a new pathway for in-situ nanoscale detection of dynamical processes in biology.