The design and properties of novel type of solid-contact ionophore-based ion-selective microelectrodes are reported. The microelectrode is based on an insulated needle-shaped metallic wire with an exposed apex. The ion-to-electron transducer is made of poly(3-octylthiophene-2,5-diyl) and placed between an ion-selective membrane and the metallic tip. The ion-selective polyvinyl chloride-based me...

This paper describes the design and fabrication of ion-sensing electrochemical paper-based analytical devices (EPADs) in which a miniaturized paper reference electrode is integrated with a small ion-selective paper electrode (ISPE) for potentiometric measurements. Ion-sensing EPADs use printed wax barriers to define electrochemical sample and reference zones. Single-layer EPADs for sensing of c...

A method was developed for determining pH differences across cell membranes using a methylammonium-selective membrane electrode, based on monitoring of the pH gradient-induced uptake of methylammonium in situ. The methylammonium electrode was constructed using calix[6]arene-hexaacetic acid hexaethyl ester as a neutral carrier and bis(2-ethylhexyl) sebacate as a membrane solvent in a poly(vinyl ...

Different causes can trigger imbalances on homeostatic mechanisms between intracellular and extracellular compartments resulting in abnormal blood potassium concentrations (hypo or hyperkalemia). This lead to serious consequences, even a life-threatening situation. Early diagnosis, treatment follow-up are essential minimize critical impacts patients. Bedside determination of is not accessible a...

Microelectrodes are the basis of the techniques discussed in this book. They are used for: (1) potential recording; (2) current injection; (3) introduction into the cell of ionselective resins for measuring potential or determining the free concentration of cytosolic constituents. (1) and (2) are the procedures underlying conventional microelectrode recording, voltage-clamping and patch-clampin...