are developing carbon nanotube-modified microelectrodes for
in vivo sensors. Carbon nanotubes have interesting
electrical, chemical and mechanical properties. In
electrochemical research, the conductivity of the tubes, a
consequence of their electronic properties, has been
exploited as a means of promoting electron transfer. A
variety of biologically-relevant, redox-active species have
been studied at carbon nanotube-modified electrodes
including hydrogen peroxide, NADH, cytochrome C, dopamine,
and proteins. While the use of carbon nanotubes in
biosensors is promising, few studies have addressed the need
for fast detection of biological molecules in order to
follow the kinetics of biological responses.
Our aim is to characterize detection of neurotransmitters at carbon nanotube-modified electrodes with fast scan cyclic voltammetry. Our hypothesis is that adding carbon nanotubes will increase the electrode surface area, increasing the number of adsorption sites that will lead to greater sensitivity for adsorbed species. We have studied various methods for fabricating nanotube electrodes, primarily dip-coating CNTs onto carbon-fiber microelectrodes (CFMEs). We have also tested CNT yarn and fiber microelectrodes as sensors and find they have unique surface properties that lead to good temporal resolution. We also are growing aligned CNTs and other forms of graphene on electrode surfaces. Recently we have characterized carbon nanospikes and carbon nanopipettes for neurotransmitter detection.
Growing carbon nanomaterials is done at Oak Ridge National Lab. We also characterize the surface of our CNT based electrodes with surface techniques such as SEM, TEM, Raman, EDS, and laser scanning microscopy, mostly performed at Oak Ridge National Lab.
Diagram of a single-walled nanotube.