A Solid-contact Pb²⁺-selective Electrode with Carbon Nanotubes by Electrodeposition as Ion-to-electron Transducer

Abstract

A novel all-solid-state polymeric membrane Pb²⁺-selective electrode was developed by electrodepositing the CNTs films on the glassy carbon (GC) electrode, and characterized by electrochemical impedance spectroscopy (EIS), chronopotentiometry, and water layer test. The results showed that the electrodeposited CNTs films formed a well interconnected spaghetti-like structure on the GC substrates and increased the low-frequency capacitance of electrode from the EIS curves. The electrode has excellent ion-to-electron transducing ability, showing a Nernstian response of 29.0 mV per decade in the Pb²⁺ concentrations range of 10⁻³–10⁻⁸ M. No water film was observed on the surface of the electrode for long-term measurements. The research demonstrated a new strategy for the fabrication of robust potentiometric ion sensors.