Improved formulation(s), device(s), and method(s) for producing ion-selective electrodes (ISEs) that comprise at least one photo-curable, epoxy-based, ion-selective chloride membrane(s) compounds that can be pre-mixed together to form a singularly-dispensed mixture for the formation of an ion-exchange resin membrane(s) for incorporation and use in a chloride ISE.

Methods and devices for quantifying creatinine in a test sample are provided. The test sample is contacted with a sensing composition to obtain a product comprising a hydantoin-transition metal complex and ammonia. The sensing composition comprises creatinine deaminase and a transition metal salt. The creatinine deaminase enzymatically reacts with creatinine to provide the N-methyl hydantoin and ammonia. The N-methyl hydantoin forms the hydantoin-transition metal complex with the transition salt. A potential difference is applied to the product to measure a current signal provided by the hydantoin-transition metal complex. Concentration of N-methyl hydantoin is obtained based on the measured current signal using a calibration equation. The concentration of N-methyl hydantoin is correlated with concentration of creatinine to quantify the creatinine in the test sample.

A method of dialysis is provided that includes sensing the concentration of potassium in a patient's blood serum, in used dialysate resulting from treating the patient, or in both. The method involves generating a sensed value of the concentration of potassium, comparing the sensed value with one or more values stored in a memory, and generating a control signal based on the comparison. Supplemental potassium solution is infused into the treatment dialysate, based on the control signal. The comparison can be made to patient-historical data, population data, or both.

A reference electrode for electrochemical measurement includes a substrate, an electrode portion on the substrate, and an ion-sensitive film covering the electrode portion and including an inorganic salt and an organic substance. The electrode portion and the inorganic salt include an anion of the same element. In a top view of the electrode portion, the maximum shortest distance from any point in the electrode portion to the outer perimeter of the electrode portion is about 0.3 mm or less.

Embodiments of the present disclosure pertain to ion-selective electrodes that include a metal-organic framework and an electrode surface. The metal-organic framework is associated with the electrode surface in a manner that forms an interface between the metal-organic framework and the electrode surface. Additional embodiments pertain to methods of detecting an ion in a sample by associating the sample with the ion-selective electrodes of the present disclosure. The metal-organic frameworks of the ion-selective electrodes mediate ion-to-electron transduction through the interface between the metal-organic and the electrode surface. Thereafter, the presence or absence of the ion in the sample is detected by detecting a change in potential of the ion-selective electrode and correlating the change in the potential to the presence or absence of the ion. The metal organic frameworks may simultaneously mediate ion sensing and ion-to-electron transduction through the interface between the metal-organic frameworks and the electrode surface.

The present disclosure relates to an electrochemical sensor for determining a measurand correlating with a concentration of an analyte in a measuring fluid, comprising: a sensor membrane designed to be in contact with the measuring fluid for detecting measured values of the measurand; a probe housing which has at least one immersion region designed for immersion into the measuring fluid, wherein the sensor membrane is arranged in the immersion region of the probe housing; and a measurement circuit which is at least partially contained in the probe housing and is designed to generate and output a measurement signal dependent on the measurand, wherein the sensor membrane contains an optically detectable substance for marking the sensor membrane.

A system for separating and analyzing a discrete sample of multiphase fluid includes a separation vessel having a first inner chamber containing a discrete sample of multiphase fluid, and an analytical cell in fluid communication with the separation vessel. The analytical cell has a second inner chamber containing a diluted aqueous liquid phase sample for analysis. The system further includes probes disposed in the second inner chamber, each probe having a sensing area at a distal end, and being oriented in the second inner chamber such that the sensing area is immersed in the diluted aqueous liquid phase sample contained in the second inner chamber. The plurality of probes include a first probe whose sensing area surface is coated with a first ion-exchange membrane; and a second probe whose sensing area surface is coated with a second ion-exchange membrane, the second ion-exchange membrane being different from the first ion-exchange membrane.

The ion sensor of the present invention is a current measurement type ion sensor that measures a current to measure a target ion, and includes an organic phase retaining layer containing an organic phase capable of forming an interface with the sample containing the target ion, a first electrode to which the organic phase retaining layer is laminated and containing a first insertion material composed of an inorganic compound, a second electrode arranged so as to face the organic phase holding layer and in contact with the sample.

In a reference electrode for the potentiometric measurement of ion concentrations, comprising a swellable polymer body filled with at least one electrolyte salt and a potential sensing element of the second type located in the polymer body, preferably of the Ag/AgCl type, the polymer body is composed of preferably organic, hydrophobic prepolymer segments, which are three-dimensionally crosslinked by preferably organic, hydrophilic polymer chains.

The invention provides a variety of novel devices, systems, and methods of utilizing mixed-ionic-electronic conductor (MIEC) materials adapted to function with an applied current or potential. The materials, as part of a circuit, are placed in contact with a part of a human or nonhuman animal body. A sodium selective membrane system utilizing the MIEC is also described.