Speaker
Description
Nitrogen-vacancy (NV) centre nanodiamonds are powerful biophysical probes that enable precise measurements of local environments through optical detection. The NV defect is accessible via optically detected magnetic resonance (ODMR), where shifts in the resonance frequencies are sensitive to temperature, strain, and electromagnetic fields. Achieving dynamic and accurate spatial control of these probes, for instance, using optical tweezers, allows targeted sensing and enhances measurement precision. This would be particularly useful in biological systems, where precise probe positioning provides a valuable sensing modality.
However, trapping nanodiamonds—and nanoparticles, in general—introduces significant challenges for optical tweezers experiments in both manipulation and sensing. Their small size results in increased thermal motion and weak scattering cross-sections. We circumvent some of these challenges by combining nanodiamonds with vaterite microspheres. Although this sacrifices nanoscale operation, it provides improved mechanical control and trapping stability. This approach also intrinsically couples mechanical measurements of the vaterite probe with the quantum sensing capabilities of fluorescent nanodiamonds. This creates a promising multi-modal technique capable of simultaneous microrheological, temperature, and magnetic-field measurements. The added rotational control of nanodiamonds enables phase-sensitive detection schemes and could enhance magnetic field sensitivity by actively aligning the NV axis during measurements.
Here, we demonstrate key components of an integrated platform combining optical manipulation, controlled NV alignment, and magnetic-field sensing using vaterite-nanodiamond probes.
| I am the presenting author | Yes |
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