Silicon Vacancy (SiV-) Nanodiamonds as High Performance Near Infrared Emitters for Live Cell Imaging and Particle Tracking

Using tailored nanodiamonds with negatively charged silicon-vacancy (SiV^-) color centers we performed a series of intracellular experiments. These nanodiamonds with SiV^- centers (NDs-SiV^-) were obtained by high-pressure high-temperature (HPHT) synthesis based on metal catalysts-free hydrocarbon HPHT growth. They were coated by a polypeptide biopolymer allowing efficient cellular uptake. High photostability and narrow emission in the near infrared region allows tracking of functionalized NDs-SiV^- in living cells. The excellent optical properties render NDs-SiV^- promising nanoemitters for various bioimaging applications. Furthermore, cellular tracking with detailed time, spatial, and spectral information paves the way to intracellular thermometry based on NDs-SiV^-.