title: Solid-contact pH-selective electrode using multi-walled carbon nanotubes.
abstract: Multi-walled carbon nanotubes (MWCNT) are shown to be efficient transducers of the ionic-to-electronic current. This enables the development of a new solid-contact pH-selective electrode that is based on the deposition of a 35-microm thick layer of MWCNT between the acrylic ion-selective membrane and the glassy carbon rod used as the electrical conductor. The ion-selective membrane was prepared by incorporating tridodecylamine as the ionophore, potassium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate as the lipophilic additive in a polymerized methylmethacrylate and an n-butyl acrylate matrix. The potentiometric response shows Nernstian behaviour and a linear dynamic range between 2.89 and 9.90 pH values. The response time for this electrode was less than 10 s throughout the whole working range. The electrode shows a high selectivity towards interfering ions. Electrochemical impedance spectroscopy and chronopotentiometry techniques were used to characterise the electrochemical behaviour and the stability of the carbon-nanotube-based ion-selective electrodes.
authors.affiliation: Department of Analytical and Organic Chemistry, Universitat Rovira i Virgili, 43007 Tarragona, Spain.
authors.forename: Gastón A
authors.initials: GA
authors.lastname: Crespo
authors.forename: Derese
authors.initials: D
authors.lastname: Gugsa
authors.forename: Santiago
authors.initials: S
authors.lastname: Macho
authors.forename: F Xavier
authors.initials: FX
authors.lastname: Rius