Fluorescent Nanodiamonds

3Color Centers in Diamond

In this chapter, we will discuss the key features of nanodiamonds that are relevant to the development of fluorescent nanodiamonds (FNDs) and their many uses in biotechnology and beyond. Up till now, we have surveyed nanotechnology in previous chapters starting with its historical development and focusing, in particular, on the nanocarbon materials. With a general introduction to nanodiamonds (Chapter 2), we have learned some methods commonly used to prepare man‐made diamonds and the fundamental properties shared by all diamonds and nanodiamonds alike. In this and the following two chapters, we are about to find out that nanodiamonds can glow (Chapter 3), support (Chapter 4), and is safe to use (Chapter 5). These unique features have made nanodiamonds a superior material for a fast‐growing list of applications at present time and in the coming future.

First comes an optical property that puts a touch of color on diamond. After all, who can turn away from the speckles of a diamond with an irresistible color destined to capture our hearts? It is only fitting to start with color centers in diamond.

Color centers are crystal defects that absorb light in a spectral region where the crystal itself has no absorption [1]. The term “color center” is derived from the German word Farbenzentren, which was first discovered in alkali halide crystals by Pohl and coworkers in the 1930s [2]. It has later been confirmed both experimentally and theoretically that the ...