The fabrication and application of an intracellular K + -selective microelectrode is demonstrated. ZnO nanowires with a diameter of 100–180 nm and a length of approximately 1.5 μm are grown on a borosilicate glass microcapillary. The ZnO nanowires were coated by a K + -ionophore-containing membrane. The K + -selective microelectrode exhibited a K + -dependent potentiometric response versus an A...

The construction and general performance characteristics of three piezoelectric quartz crystal sensors responsive to the pentoxyverine are described here. This kind of non-potentiometric sensing method is based on use of ion-pair complexes of the pentoxyverine cation with three counter anions, namely, tungstophosphate, tetraphenylborate and picrolonate. The complexes were embedded in a PVC matr...

A new PVC membrane electrode for the triiodide ion based on a charge-transfer complex of iodine with 7,16-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane as a membrane carrier was prepared. The electrode exhibits a Nernstian response for triiodide ions over a wide concentration range (1.0 x 10(-1)-1.0 x 10(-5) M) with a slope of 59.3 +/- 0.9 mV decade(-1) and a detection limit of 6.3 x 10...

Potentiometric sensors require the implementation of conducting wires for signal transduction, but this is impractical for the readout of individual nanoparticles. It is here demonstrated for the first time that the potentiometric response of ion-selective nanospheres can be observed with voltage-sensitive dyes, thereby converting nanoscale electrochemical signals into an optical readout. No re...

An iodide ion-selective PVC membrane sensor based on copper (Π)-bis-Nphenilsalicyldenaminatocomplex as a novel sensing material is successfully developed. Theelectrode showed a good selectivity for iodide ion with respect to common inorganic anions. Thesensor exhibited a good linear response with slope of _58.6 ± 0.4 mV per decade over theconcentration range of 5.0 × 10-6 to 1.0 × 10-1 mol L-1,...

This work reports a very simple approach for creating a synthetic antibody against any protein of interest and its application in potentiometric transduction. The selected protein was Breast Cancer Antigen (CA 15-3), which is implicated in breast cancer disease and used to follow-up breast cancer patients during treatment. The new material with antibody-like properties was obtained by molecular...

Two analytical methods, which prove the utility of a potentiometric flow injection technique for determining various redox species, based on the use of some redox potential buffers, are reviewed. The first is a potentiometric flow injection method in which a redox couple such as Fe(III)-Fe(II), Fe(CN)(6) (3-)-Fe(CN)(CN)(6) (4-), and bromide-bromine and a redox electrode or a combined platinum-b...

Unlike the overwhelming majority of nanopore sensors that are based on the measurement of a transpore ionic current, here we introduce a potentiometric sensing scheme and demonstrate its application for the selective detection of nucleic acids. The sensing concept uses the charge inversion that occurs in the sensing zone of a nanopore upon binding of negatively charged microRNA strands to posit...

The construction and general performance of thirteen new polymeric membrane sensors for the determination of fexofenadine hydrochloride based on its ion exchange with reineckate, tetraphenylborate and tetraiodomercurate have been studied. The effects of membrane composition, type of plasticizer, pH value of sample solution and concentration of the analyte in the sensor internal solution have be...

Use of a novel rotating polycation-sensitive polymer membrane electrode yields sensors that can serve as simple potentiometric titration endpoint detectors for the determination of three FDA approved low-molecular-weight heparin (LMWH) anticoagulant drugs (Fragmin, Normiflo, and Lovenox). The rotating electrode configuration dramatically improves the reproducibility and increases the sensitivit...