An online calibration system for an electrochemical sensor. The calibration system comprises a calibration electrode coupled with a redox species, where the redox species is configured to control a pH of a reference solution local to the calibration electrode, such that when a voltammetric signal is applied to the calibration electrode the output generated from the calibration system is determined by the local environment pH. The output signal from the calibration system is used to calibrate a reference potential generated by a reference system of the electrochemical sensor to correct for drift in the reference potential when the electrochemical sensor is being used. The calibration electrode may be disposed in a reference cell of the electrochemical sensor.

Disclosed are methods and devices for biomolecular detection, comprising a nanopipette, exemplified as a hollow inert, non-biological structure with a conical tip opening of nanoscale dimensions, suitable for holding an electrolyte solution which may contain an analyte such as a protein biomolecule to be detected as it is passed through the tip opening. Biomolecules are detected by specific reaction with peptide ligands chemically immobilized in the vicinity of the tip. Analytes which bind to the ligands cause a detectible change in ionic current. A sensitive detection circuit, using a feedback amplifier circuit, and alternating voltages is further disclosed. Detection of IL-10 at a concentration of 4 ng/ml is also disclosed, as is detection of VEGF.

An electrochemical sensor for potentiometric measurements in a measurement medium has a sensor head (201) at an end of a longitudinal sensor body (203). A sensing electrode (210) and a reference electrode (220) are disposed within the longitudinal sensor body. A liquid junction (223) is established between the reference electrode and the sensing electrode. The sensor is characterized by a protective outer shaft (250) with a polymeric sensor sleeve (230), which is electrically isolating, disposed within the protective outer shaft.

A system for obtaining a pH measurement includes a disposable probe and a reader. The disposable probe comprises multiple indicating electrodes and at least one reference electrode. The reader is configured to operably engage with the disposable probe and provide pH information of a sample.

This disclosure relates to creatinine biosensors and the uses thereof. More specifically, this disclosure describes potentiometric creatinine sensors which utilizes one or both of a type of enzyme capable of directly producing ammonium ions (NH4+) as a consequence of coming into contact with a liquid sample and an internal fill solution with a low free ammonium ion concentration.

Methods and devices for measuring the status of oxidative stress on the surface or in a biological matrix involve use of at least one compound selected from NADH, NADPH, Cyt C (Fe.sup.2+) or H.sub.2O.sub.2.

We describe a soil chemistry sensor for in-situ soil chemistry sensing, the sensor comprising a probe incorporating a first, ion-selective electrode and a second, reference electrode, wherein said ion-selective electrode comprises a first-electrode housing defining a first lumen having an ion-selective plug towards a distal end, said first-electrode including a first conductor in a first electrolyte, wherein said reference electrode comprises a second electrode housing defining a second lumen having a porous reference electrode plug towards a distal end, said second electrode including a second conductor in a second electrolyte, wherein said ion-selective plug and said porous reference electrode plug are within 10 mm of one another, and wherein said porous reference electrode plug and said ion-selective plug each comprise a polymer.

A potentiometric sensor that includes a housing and working electrode is provided. The housing includes a reference electrode, a first hydrogel that contains a reference solution, and a salt bridge. The sensor is wearable and can be used for continuous on-body sweat measurements.

The purpose of the present invention is to realize a dew point measurement in which the generation of dew condensation is directly detected and the detection can be performed without using any optical system. In particular, the purpose of the present invention is to realize a dew point measuring device that is compact and has a high sensitivity. According to one embodiment of the present invention, a sudden change in current values before and after the dew point is detected by detecting the dew condensation to detect a galvanic current that flows due to a water droplet attached onto a surface of an insulating substrate on which thin wires of dissimilar metals are juxtaposed, and by controlling the temperature on the surface of the substrate. In this way, the dew point measurement in which the dew point can be directly measured and a measurement with simple configuration and high accuracy can be performed can be realized.

The present disclosure relates to a sensor arrangement including a housing, connectable to a process container and including a guiding passageway formed therein, and a sensor body displaceable in the guiding passageway between a first position and a second position, wherein the sensor body has at least one end section, which can be moved out of the housing and which includes at least one sensor element serving for registering a measured variable of a measured medium, wherein the at least one sensor element is arranged in the first position of the sensor body within a chamber formed in the housing and, in the second position of the sensor body, outside of the housing, and wherein the at least one end section of the sensor body has a base and a peripheral surface, wherein the at least one sensor element forms a part of the peripheral surface.