A general approach to one-step fabrication of single-piece nanocomposite membrane based Pb²⁺-selective electrodes

A simple and general approach leading to well-dispersed and surfactant-free multi-walled carbon nanotubes (MWCNT) based single-piece Pb²⁺-selective nanocomposite membrane is proposed. The single-piece solid-contact Pb²⁺-selective electrodes were prepared via one-step drop casting the ultrasonicated suspension mixture on the golden electrodes. The obtained electrodes exhibited a Nernstian response slope of 29.0 ± 0.2 mV/decade in the linear range from 2.0 × 10⁻³ to 2.0 × 10⁻⁹ M and a low detection limit of 4.0 × 10⁻¹⁰ M. Due to the inherent high capacitance and hydrophobicity of nanocomposite membrane, excellent long-term potential stability and absence of water films were observed. Moreover, the sensor showed good resistance to interfering agents such as redox couple, light and gases. In addition, the proposed electrodes were demonstrated to be feasible for Pb²⁺ determination in tap water. Overall it was demonstrated as an appealing sensor for lead (II) detection for environmental and clinical applications.