Technique - (3) Real-time 3D single-particle tracking spectroscopy

Type: Experimental

Description: Feedback-based confocal tracking of single fluorescent particles/molecules through 3D space in complex, heterogeneous environments.

Department(s)/lab(s): EMBL Australia Node in Single Molecule Science, UNSW Medicine and Health | Ananthanarayanan Cell Biology and Advanced Microscopy Group @ UNSW
Summary:

Ananthanarayanan was awarded the Royal Microscopical Society Life Sciences Award in 2025 for the use of novel microscopies in cell biology. Her group images individual motor proteins — dynein, kinesin — and the mitochondria they transport, in living cells, at single-molecule sensitivity, combining light-sheet and TIRF-class imaging with particle tracking to ask how organelle positioning and mitochondrial dynamics are controlled. The methodological emphasis is on getting single-molecule sensitivity inside a live cell rather than in vitro, which is the hard version of the problem. Positioned against the established body of NV-ensemble quantum sensing work — DEER, nanoscale NMR and T1 relaxometry protocols operating at pT/sqrt(Hz) field sensitivity — this is the closest thing at UNSW to a biological end-user for an in-cell quantum sensor: the mitochondrial systems she studies are precisely where NV nanodiamond thermometry and free-radical relaxometry at pT/sqrt(Hz) have been aimed, and she has the live-cell imaging infrastructure to validate any such measurement independently.

Department(s)/lab(s): Physics | LuMIn - NV & Nanodiamond Biosensing (Treussart) @ ENSPS
Summary:

Treussart uses fluorescent nanodiamonds (NV centres) as photostable bio-probes: intracellular single-particle tracking, nanoscale thermometry/magnetometry, and multimodal biosensing in cells and organisms, alongside super-resolution imaging - a direct NV-ensemble-to-biology bridge. In the broader landscape of NV-centre ensemble quantum sensing (DEER, nano-NMR, T1 relaxometry) operating near pT/sqrt(Hz) sensitivity, this work is applied here to living cells via nanodiamond probes.

Department(s)/lab(s): Chemistry | Haw Yang Lab @ Princeton
Summary:

Yang's experimental physical chemistry lab designs new instrumentation to track single proteins, nanoparticles, and other emitters in three dimensions in real time within complex, heterogeneous environments, including a recent time-gated two-photon platform for high-speed 3D single-particle tracking. His group applies these single-molecule tracking and orientation-resolved imaging tools to protein conformational dynamics, functional nanostructures, and active-matter systems.