THE molecular equivalent of a Venus flytrap could capture water-borne nuclear waste.
So say and Nan Ding from Northwestern University in Evanston, Illinois. They have synthesised a sulphide-containing material with a flexible structure that mimics the flytrap鈥檚 jaws.
The structure has 鈥渨indows鈥� measuring 0.8 nanometres by 0.3 nanometres 鈥� just large enough for caesium ions to squeeze through. Once inside, the caesium bonds with sulphide ions, and this changes the material鈥檚 structure in a way that closes the windows and traps the caesium.
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鈥淭he trigger for closing the trap comes from the caesium-sulphide interactions in the material,鈥� says Kanatzidis. Even if other ions such as sodium are present, they bond so strongly to water molecules that they can鈥檛 react with the sulphide, he says (Nature Chemistry, ).
Kanatzidis thinks the flytrap could be used to trap radioactive caesium at nuclear disposal sites.
It鈥檚 elegant chemistry, says Alan Dyer at the University of Salford, UK, but it鈥檚 unclear if it could perform as well as existing materials. 鈥淚鈥檇 want a lot more comparative studies to see what its true worth was,鈥� he says.
