Fluorescent Diamond Particles for Bioimaging and Quantum Sensing

Diamond nanoparticles containing fluorescent color centers exhibit a favorable combination of optical properties including photostability that outlasts quantum dots and molecular probes, a broad emission color palette, and excellent biocompatibility. Fluorescent nanodiamonds containing nitrogen-vacancy (NV) color centers enable unique quantum sensing capabilities by reporting on nearby analytes, such as free radicals and other paramagnetic species, by decoding fluctuating magnetic fields induced by these external spins. This information can be conveniently imaged optically by adapting conventional microscopes or via hyperpolarized magnetic resonance methods. For the latter, quantum sensing is based on hyperpolarizing ¹³C nuclei in nanodiamond particles by optical pumping of NV centers and then imaging chemical information by ¹³C NMR scanners at high resolution. In this presentation, material developments for quantum sensing applications will be highlighted. The progress of several projects on quantum sensing with a biological scope under development by our team will be presented, with a more detailed focus on a near-term application such as using nanodiamond particles as sensors of paramagnetic species in biological media.