British scientists achieve breakthrough in creating ultramicroelectrodes

LONDON, May 6 (Xinhua) -- British scientists have found a way of producing carbon nanotubes in which they instantly form a highly sensitive ready-made electric circuit.

Chemistry department researchers at the University of Warwick used a form of chemical vapor deposition and lithography to create the ready-made disc-shaped single-walled carbon nanotube based ultramicroelectrodes, according to a University press release Tuesday.

The nanotubes deposit themselves flat on a surface in a random but relatively even manner and they also all overlap sufficiently to create a single complete metallic micro-circuit right across the final disc, taking up less than one percent of its surface area.

This final property makes these instant ultramicroelecrodes particularly useful for the creation of ultra sensitive sensors, the researchers said, adding that the low surface area of the conducting part of the disc means that they can be used to screen out background "noise" and cope with low signal-to-noise ratios, making them up to 1,000 times more sensitive than conventional ultramicroelecrodes sensors.

This property also produces very fast response times allowing them to respond ten times faster than conventional ultramicroelecrodes, the scientists said.

The researchers have been able to use this new method of single-walled carbon nanotube assembly to prove that it is actually the properties of the carbon nanotubes themselves that are useful for catalysis.

The new carbon nanotube assembly technique brings a further benefit to catalysis applications as the Warwick researchers have been able to use electro-deposition to quickly and easily apply specific metal coatings to the ready formed single-walled carbon nanotube microelectrode networks.

This will be of significant benefit to anyone wanting to use single walled carbon nanotube for catalysis in fuel cell technology.

As these ready made ultramicroelecrodes are carbon-based, they open up a range of new possibilities for use in living systems, said the researchers. They have already begun to explore how the sesingle-walled carbon nanotube based ultramicroelecrodes can be used to measure levels of neurotransmitters, according to the press release.