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

Abstract

Nanodiamonds (NDs) with color centers are excellent emitters for various bioimaging and quantum biosensing applications. In our work, we explore new applications of NDs with silicon-vacancy centers (SiV) obtained by high-pressure high-temperature (HPHT) synthesis based on metal-catalyst-free growth. They are coated with a polypeptide biopolymer, which is essential for efficient cellular uptake. The unique optical properties of NDs with SiV are their high photostability and narrow emission in the near-infrared region. Our results demonstrate for the first time that NDs with SiV allow live-cell dual-color imaging and intracellular tracking. Also, intracellular thermometry and challenges associated with SiV atomic defects in NDs are investigated and discussed for the first time. NDs with SiV nanoemitters provide new avenues for live-cell bioimaging, diagnostic (SiV as a nanosized thermometer), and theranostic (nanodiamonds as drug carrier) applications.

Nanodiamond–Quantum Sensors Reveal Temperature Variation Associated to Hippocampal Neurons Firing

“…In this case the NDs registered the temperature variation associated with the heating obtained by local laser irradiation of the nanorods. In another recent experiment, [ 33 ] SiV in NDs were used to for imaging and temperature measurement in HeLa cells, even if only the average temperature of the bath (by controlling the incubator temperature) was measured, without single‐cell resolution. It must be stressed anyway that, in both the above mentioned works, the temperature variation was induced by the experimenters (i.e., via laser irradiation or by changing the incubator temperature) and no authentic biological phenomenon was measured.…”

Production, surface modification, physicochemical properties, biocompatibility, and bioimaging applications of nanodiamonds

“…One of the commonly employed methods to induce NIRF in NDs is the introduction of silicon vacancy (SiV) centers (zero phonon line center = 738 nm) into NDs. 137,138 The SiV centers are created by introducing silicon precursors as impurities into the diamond growth region for HPHT diamonds 137 or detonation region for detonation NDs. 138…”

High-quality diamond microparticles containing SiV centers grown by chemical vapor deposition with preselected seeds

“…[34][35][36][37] As compared to other defects, SiV centers offer multiple advantages such as emission in the near-infrared (NIR) range, high Debye-Waller factor (DWF), narrow bandwidth, and high photo-and chemical stability. 19,37,38 Moreover, SiV emission is linearly polarized, 39 which can be used to filter out its signal from background noise, increasing the signal-to-noise ratio and contrast in fluorescence images. These factors render the SiV center a promising candidate for thermometry and bioimagingrelated applications in life sciences.…”

“…Recently, high sensitivity all-optical SiV based thermometry has been achieved by multiple groups. 19,37,38 And the above demonstrated superior features, e.g., high crystallinity, excellent SiV property and low inhomogeneity, of the SAAO ND-grown diamond microparticles also facilitate highly sensitive, and calibration-free all-optical thermometry to be performed.…”