This application describes microelectronic pH sensors that can include indicating electrodes having a substrate, an electrode disposed on the substrate, a reactive layer disposed on a portion of the electrode, and a conductive layer disposed on the reactive material and reference electrodes having similar architecture.

The present invention provides an electrochemical sensor that employs multiple electrode areas that are exposed for contact with a body fluid, e.g., when the sensor is inserted subcutaneously into a patient's skin. The exposed electrode areas are arranged symmetrically, such that a symmetrical potential distribution is produced when an AC signal is applied to the sensor. The sensors in accordance with these teachings can advantageously be used with AC signals to determine characteristics of the sensor and thus improve sensor performance. These teachings also provide a biocompatible sensor with multiple reference electrode areas that are exposed for contact with body fluid.

The inventive concepts disclosed herein are generally directed to the need to measure a microsample and obtain one or more measurement for one or more analyte in the microsample by configuring a sensor array having one or more first reference signal source interlaced with one or more analyte sensor positioned along the longitudinal axis the sensor body and a second reference signal source positioned downstream of the sensor body along a sample flow path.

An automatic analysis device 100 includes an electrolyte measurement unit 114 that executes internal standard solution measurement once or more at least before potential measurement of the specimen, and when the potential measurement of the specimen is continuously executed by the electrolyte measurement unit 114, a measurement operation of the internal standard solution before the potential measurement is changed depending on whether there is a possibility that the specimen measured immediately before is a high concentration specimen. This provides an automatic analysis device and an automatic analysis method of a specimen that are capable of improving the processing capacity of the entire device by reducing the carry-over and ensuring measurement accuracy in performing electrolyte measurement.

A calibration electrode for calibrating a reference system of an electrochemical sensor, such as a potentiometric sensor or an ion selective electrode. The calibration electrode has an active surface comprising redox functionalities. The redox functionalities set the pH of a reference solution proximal to the calibration electrode. A voltammetric signal is applied to the calibration electrode to produce a response that is determined by the set pH. The response of the calibration electrode to the voltammetric signal is used to calibrate/adjust a reference potential produced by a reference electrode of the reference system of the electrochemical sensor. This calibration corrects the detrimental effect of reference electrode drift.

The present disclosure provides for a coated, substrate for use as an electrode, the coated substrate comprising a substrate that is at least partially coated with a layer comprising a polymer and a redox active substance, wherein the polymer is a cation exchange polymer, and wherein the redox active substance is present in both an oxidised and reduced state. A method for making the isolated coated substrate, and an electrochemical apparatus using the electrode as a reference electrode, is also discussed herein.

According to at least one aspect of the present disclosure, a reference half-cell for an electrochemical sensor for measuring a medium is disclosed. The reference half-cell includes a housing defining a chamber containing an electrolyte, the housing including a wall having an aperture therethrough, and an electrode disposed in the electrolyte in the chamber. The reference half-cell further includes a reference junction disposed in the aperture such that an interface between the reference junction and the housing wall is impermeable. The reference junction is electrically or ionically conductive and impermeable to the measured medium and the electrolyte, and the reference junction enables a constant potential at the electrode. An electrochemical sensor and oxidation-reduction potential sensor employing the reference junction are also disclosed.

An electrochemical chlorine gas sensor is disclosed with a working electrode, a counter electrode, and a reference electrode. The working electrode may be coated with a nanoporous gold layer, a first solution comprising an ionic liquid, and a second solution that may be selected from a Nafion solution, a chitosan solution, an agar solution, or combinations thereof. The reference and counter electrodes may be further coated with the ionic liquid.

A method for producing a silver-silver chloride electrode includes: producing a paste by mixing silver powder, silver chloride powder, a dispersant, and fumed silica powder with a liquid silicone rubber binder; coating the paste on a substrate made of silicone rubber; curing the paste on the substrate to form an electrode containing silver and silver chloride; and immersing the electrode in a sodium chloride aqueous solution.

An electrode and a method of making an electrode includes treating polymers that contain functional groups, which by surface functionalization, such as hydrolysis, ozone treatment or carbon-carbon double-bond oxidation to produce hydroxyl functional groups on the surface. Reacting methacryloyl chloride with the resulting hydroxyl functional groups thereby providing a reactive surface. Photopolymerizing or thermal polymerization of crosslinked acrylate or methacrylate polymers on the reactive surface to produce a membrane covalently bonded to the underlying substrate. In addition such an electrode can also be produced on a polystyrene substrate by reacting methacryloyl chloride with the polystyrene substrate and photopolymerizing or thermally polymerizing to produce crosslinked acrylate or methacrylate polymers on the reactive surface to produce a membrane covalently bonded to the underlying polystyrene substrate.