A group of Taiwanese scientists has discovered a cheaper way to create tiny fragments of diamonds, similar in size to microscopic viruses and known as fluorescent nanodiamonds (FNDs), making it possible for them to be used to reveal the movement of cells around the body, or even deliver genes, according to New ScientistTech.
This function of the nanodiamonds is realized when the diamond fragments are hit with a laser; due to defects in the structure of the diamonds that absorb the laser energy and emit their own light at a different wavelength, they can fluoresce for hours afterward and be tracked in cells throughout the body.
In addition, the diamond material is relatively stable and non-toxic and is therefore an attractive material for use inside the body. But, until now, the diamond fragments have been too expensive to manufacture.
As New ScientistTech explains, FNDs are usually made when a high-energy electron beam is fired into diamond powder and then heated up to 800 °C, but a Taiwanese scientist named Huan-Chen Chang and his colleagues at the Academia Sinica have discovered that they can shoot a less intense, and thus cheaper, beam of helium ions at the diamond dust to produce FNDs with the same quality.
"The beam of helium ions knocks some carbon atoms out of the nanodiamonds, leaving vacancies behind," explains Chang. Those vacancies, he says, bond with nitrogen atoms and form flaws that allow the diamonds to absorb and re-emit laser light. The cheaper FNDs work almost as well as those produced with an electron beam. In tests, Chang said his team could track the movement of a single fluorescent nanodiamond within a cell for over 3 minutes.
Other uses for the cheaper nanodiamonds have been explored by the researchers, including monitoring stem cells in developing tissues or carrying drugs into cells.