Earthworms Roped Into Making Quantum Dots
Ordinary earthworms are proving to be a sophisticated chemistry lab: they can put together substances with unusual light-emitting properties. It is the first time organisms other than fungi and bacteria have been seen to do this. Mark Green at King’s College London has spent his career making quantum dots – nanometre-sized chunks of semiconducting metals that fluoresce intensely because of the way their electrons behave. These quantum dots have been used to improve the efficiency of solar panels and build high-tech display screens. However, to be able to use them in the body – to track cancer cells, for example – intricate and expensive chemical processes are required that can reduce the dots’ luminescence. Perhaps no longer, though: Green has found that earthworms, fed the right chemicals, can serve as a natural production line for biocompatible quantum dots.