Fluorescent nanodiamonds (FNDs) are biocompatible particles with indefinite photo-stability that have emerged as promising bioimaging probes.  FNDs with negatively charged nitrogen-vacancy (NV-) centers are superior imaging probes because they do not photobleach or blink, have a high quantum yield, large Stokes’ shift, long fluorescence lifetimes, and fluorescence emission that can be modulated by magnetic fields to improve signal:noise >100x.  Their broad fluorescence emission in the near infrared region can penetrate deep into the tissue with limited background signal from autofluorescence.  However, FND use in bioimaging has been limited thus far because of their tendency to aggregate and difficulty in functionalizing or coating their inert surface. Here, we present FND particles that have been surface treatment to resolve these issues, along with bioconjugation chemistries that have allowed for a range of in vitro and in vivo imaging applications. Furthermore, we illustrate the unique features and potential uses of FNDs from single molecule techniques to cell generation tracking to tumor spheroid uptake studies to wide-field background-free imaging through magnetic modulation to image lymph node through tissue.

A presentation by Ambika Bumb