DNA-bonded crystals herald a new chemistry

摘要

ARTIFICIAL crystals based on an alternative chemistry of DNA-bonded nanoparticles, rather than chemically bonded atoms, can now be created on demand. In nature, the sizes and properties of the atoms that make up a crystal - a regular array of bonded atoms - determine its structure. That's why each sodiun atom in sodium chloride is surrounded by six chlorines and vice versa, whereas in galliurr arsenide, each atom has only four nearest neighbours. To create crystal structures that do not depend on the size and nature of the component atoms, Chad Mirkin of Northwestern University in Evanston, Illinois, and colleagues used gold nanoparticles instead of atoms. To these, they attached dozens of DNA molecules that stuck out like hairs. Their ends were single-stranded DNA and so could form a bond to a complementary section of DNA attached to another gold particle. As more connections developed, a crystal formed.