© 2008 ACS

Semiconducting nanowires are attractive for building complex arrays of nanoscale devices such as field-effect transistors. An efficient way of connecting the devices would be to build multiple devices onto a single nanowire. For this to be possible, ultralong wires with uniform structure and electronic properties would be needed. Researchers from Hanyang University and Harvard University have now grown millimetre-long silicon nanowires that fulfil these requirements.

Charles Lieber and colleagues1 used a nanocluster-catalysed vapour–liquid–solid growth method, with disilane as the reactant and gold as the catalyst. The nanowires, synthesized at temperatures of 390–410 °C, were almost 100 times longer than ones that have been produced with a similar method using silane as the reactant, and the growth rate was 130 times faster. A one-dimensional array of field-effect transistors was then built, with approximately 100 independent devices on each nanowire. The devices showed good uniformity over millimetre length scales, suggesting that the electronic properties of the wires are homogeneous throughout.

By functionalizing the field-effect transistors with antibodies, an approach was demonstrated for detecting cancer marker proteins with the single-nanowire device.