Carbon nanotubes based nanoelectrode arrays: Fabrication, evaluation, and application in voltammetric analysis

Fabrication, electrochemical characterization, and applications of low-site density carbon nanotubes based nano-electrode arrays (CNTs-NEAs) are reported in this work. Spin-coating of an epoxy resin provides a new way to create the electrode passivation layer effectively reducing electrode capacitance and current leakage. Cyclic voltammetry showed the sigmoidal shape curves with low capacitive current and scan-rate-independent limiting current. Square-wave voltammetry showed well-defined peak shapes in voltammograms of K ₃Fe(CN)₆ and 4-acetamidophenol (acetaminophen) and the peak currents to be proportioned to their concentrations, demonstrating the feasibility for voltammetric analysis of the CNTs-NEAs. The CNTs-NEAs were also used successfully for voltammetric detection of trace concentrations of lead(II) at ppb level at first-time. The CNTs-NEAs provide an excellent platform for ultra sensitive electrochemical sensors for chemical and biological sensing.