Earthworm guts become factory for nanoparticles

Enlarge / Meet the latest quantum dot assembly factory.

Colorado State

Quantum dots are nanoscale-sized pieces of semiconductor. Their small size ensures that quantum effects, like the Pauli exclusion principle, influence the behavior of electrons within them. This gives the dots properties that a bulk material with the same composition lacks, and it makes them appealing candidates for things like tiny lasers, photovoltaic materials, and LEDs.

Another area where they've shown promise is medical imaging. In terms of absorbing and emitting light, quantum dots behave much like the fluorescent molecules we can use to label cells of interest. But, since their fluorescent properties depend on the shape of the particles rather than the chemical structure of a molecule, they are much less prone to undergoing reactions that destroy their fluorescence. The problem is that most semiconductors aren't especially biocompatible, meaning additional chemical reactions need to be performed before the dots can attach to or enter cells.

Some researchers have started to look towards making the dots in biological systems, figuring that the output would necessarily be biocompatible. After some successes with bacteria and yeast, they've moved on to a larger target: the earthworm. And it appears to work very well.