Silicon-Vacancy Nanodiamonds as High Performance Near-Infrared Emitters for Live-Cell Dual-Color Imaging

Intracellular imaging is limited by a short bleaching time of fluorescent molecules and particles. In our work we used nanodiamonds with silicon-vacancy centers (SiV) obtained by high-pressure high-temperature synthesis based on metal-catalyst-free growth. They are coated with a polypeptide biopolymer that allows efficient cellular uptake. Our results demonstrate that high photostability and narrow emission in the near-infrared region of nanodiamonds with SiV allow live-cell dual-color imaging and intracellular tracking. Such a system has broad potential applications, which is not limited to live-cell bioimaging, but also include diagnostic (SiV as a nanosized thermometer) and theranostic (nanodiamonds as drug carrier).