Low Impedance Functionalised Carbon Nanotube Electrode Arrays for Electrochemical Detection

Abstract Studying electrical and chemical signals of individual cells in situ requires the use of electrodes with ≤20 µm diameter. However, electrodes of this size generally produce high impedance thus perturbing recording of signals released from individual cells. Here, we substantially improve on commercial impedance values for electrodes of 20 µm diameter by using functionalised nanoscale carbon nanotubes (CNTs) as the electrode material. Electrochemical impedance spectroscopy reports an impedance of 2.43±0.45 kΩ at 1 kHz for functionalised CNT electrodes. This is a 10‐fold improvement on commercial electroplated Pt electrodes of the same size and will allow increased sensitivity of detection.