Review Article: Synthesis, properties, and applications of fluorescent diamond particles

Abstract

Diamond particles containing color centers—fluorescent crystallographic defects embedded within the diamond lattice—outperform other classes of fluorophores by providing a combination of unmatched photostability, intriguing coupled magneto-optical properties, intrinsic biocompatibility, and outstanding mechanical and chemical robustness. This exceptional combination of properties positions fluorescent diamond particles as unique fluorophores with emerging applications in a variety of fields, including bioimaging, ultrasensitive metrology at the nanoscale, fluorescent tags in industrial applications, and even potentially as magnetic resonance imaging contrast agents. However, production of fluorescent nanodiamond (FND) is nontrivial, since it requires irradiation with high-energy particles to displace carbon atoms and create vacancies—a primary constituent in the majority color centers. In this review, centrally focused on material developments, major steps of FND production are discussed with emphasis on current challenges in the field and possible solutions. The authors demonstrate how the combination of fluorescent spectroscopy and electron paramagnetic resonance provides valuable insight into the types of radiation-induced defects formed and their evolution upon thermal annealing, thereby guiding FND performance optimization. A recent breakthrough process allowing for production of fluorescent diamond particles with vibrant blue, green, and red fluorescence is also discussed. Finally, the authors conclude with demonstrations of a few FND applications in the life science arena and in industry.

The Fate of Lipid-Coated and Uncoated Fluorescent Nanodiamonds during Cell Division in Yeast

“…They have a relatively broad size distribution and irregular shape [25]. According to the vendor, these particles are irradiated with an electron beam at 3 MeV to 5 × 10 19 e/cm 2 fluence followed by high temperature annealing above 600 • C under vacuum for 2 h [26]. The NV content was measured by the manufacturer by electron paramagnetic resonance to be approximately 2-2.5 ppm.…”

Evaluation of the Oxidative Stress Response of Aging Yeast Cells in Response to Internalization of Fluorescent Nanodiamond Biosensors

“…In this study, fluorescent nanodiamonds (FNDs) with an average hydrodynamic diameter of 70 nm (Adamas Nano, Raleigh, NC, USA, https://www.adamasnano.com/) were used. These are produced by grinding high-pressure high-temperature diamonds and irradiation with three MeV electrons to 5 × 10 19 e/cm 2 fluence to raise the number of NV centers to an average of 300 centers per diamond (determined by electron paramagnetic resonance by the manufacturer) [15]. The surface chemistry of the FNDs is oxygen-terminated, as a result of an acid treatment by the manufacturer.…”

Spatially controlled fabrication of single NV centers in IIa HPHT diamond

“…Considering this, we estimated the nitrogen concentration in {001} growth sector to be < 10 16 cm -3 or 50 ppb (at least one order lower than in {111}). It is known that due to high growth temperature in TG-HPHT process vacancy complexes are unstable and there are almost no detectable NV centers in as-grown crystals even in {111} growth sector [20]. Based on this, we decided to use the vacancy-driven scheme ( Fig.…”