Glowing Quantum Dots

Researchers recently discovered an inexpensive way to produce fluorescent carbon nanoparticles from coal, an innovation that has tremendous potential for biomedicine, particularly in imaging applications for observing molecular structures in cells and tissues. In comparison to conventional fluorescent dyes typically used for that purpose, they tend to be brighter and glow for longer periods.

The method involves agitating coal with sound waves, treating it with acid, and then heating it for 24 hours. The resultant particles consisted of a carbon compound, one atom thick, deposited in several layers in a highly ordered structure.

Interestingly, different types of coal (bituminous, anthracite, and coke) each yielded different size particles ranging from 2 to 40 nanometers in size. They also found that each size particle emitted a distinctly different color, making it possible to image different biomolecules with multiple colors using a single light source.