Carbon nanotube band electrodes for electrochemical sensors

Utilization of carbon nanotubes (CNTs) in fabrication of electrodes for electrochemical detection often faces a conflicting goal: achieving both high response current and high mass transfer coefficient. Typically, electrodes made in a form of CNT ensembles offer high response current as a result of the large number of CNTs. However, these electrodes have substantially low mass transfer coefficients due to overlapping of diffusion fields between neighboring CNTs. To resolve this conflict, we design band electrodes made of vertically-aligned CNT (CNBEs), which are macro-sized in length and submicro-sized in width. We show that the distinct dimensions of the CNBEs allow both high response currents and mass transfer coefficients. We also demonstrate that CNBEs offer excellent detection performances including wide linear range, high sensitivity, and low limit of detection in channel flow voltammetry.