Electro-chemical and biological properties of carbon nanotube based multi-electrode arrays

A novel class of micro-electrodes was fabricated by synthesizing high density carbon nanotube islands on lithographically defined, passivated titanium nitride conductors on a silicon dioxide substrate. Electrochemical characterization in phosphate buffered saline of these new electrodes reveals superb electrochemical properties marked by featureless rectangular cyclic voltammetry curves corresponding to a DC surface specific capacitance and a volume specific capacitance as high as 10 mF cm(-2) and 10 F cm(-3), respectively. These electrodes are also characterized by a slowly varying impedance magnitude over the range of 1 Hz to 20 kHz. High fidelity extracellular recordings from cultured neurons were performed and analysed to validate the effectiveness of the fabricated electrodes. The enhanced electrochemical properties of the electrodes, their flexible and simple micro-fabrication preparation procedure as well as their bio-compatibility and durability suggest that carbon nanotube electrodes are a promising platform for high resolution capacitive electrochemical applications.