Light Emitting Dots Produced By Earthworms

One of the more interesting ideas these days is to use biological organisms to produce needed drugs, chemical compounds and other substances that can't be synthesized in a lab or a normal industrial process.

A recent example is getting earthworms to produce nanometre-sized chunks of semiconducting metals that fluoresce intensely because of the way their electrons behave. These "quantum dots" are being used in applications such as solar panels and display screens.

It seems that when you feed the worms the right mix of chemicals, they make the dots. Mark Green, at King's College London, exposed the worms to cadmium chloride and sodium tellurite and found that they moved the metals to the equivalent of their liver, where they became cadmium telluride quantum dots. The earthworms make dots because they want the metals out, says Green. "It's a biodefence mechanism."

Another useful application: the dots were able to light up cancer cells in an imaging experiment.

If you want to read more, here's a link to the article in New Scientist.