A Nanodiamond is Forever: Functionalizable fluorescent nanodiamonds that do not photobleach or blink for in vitro and in vivo imaging

A. Bumb, S. Sarkar, M. Brechbiel, K. Neuman
National Heart, Lung, & Blood Institute, US

Keywords: near infrared imaging probe, nanoparticles, optical imaging, nanodiamonds, background-free imaging


Fluorescent nanodiamonds (FNDs) are a new category of nanoparticles with optical properties that make them superior imaging probes that could replace commonly used fluorescence agents (i.e. dyes and quantum dots). In particular, their near infrared fluorescence makes them ideally suited for imaging in patients. However, FND use has been limited thus far because of difficulty in functionalizing or coating their inert surface and because of their tendency to aggregate. To solve these issues, we have coated nanodiamonds with silica using an innovative liposome-based coating process. Having such an optically superior, stable, and functionalizable nanoparticle essentially introduces a new building block to the fields of nanotechnology and nanomedicine, providing for a plethora applications. We have illustrated the unique features and potential uses of FNDs from single molecule to in vivo imaging with several applications: (1) high spatial and temporal resolution 3-D tracking over extended periods of time, (2) as stable fiducial markers for ultra high resolution microscopy across multiple wavelengths, and (3) wide-field background-free imaging through magnetic modulation of FND emission combined with computational lock-in signal recovery.