There is provided a chloride selective membrane including an epoxide-based matrix reacted with a stoichiometric amount of an amino compound and an activator such that the epoxide-based matrix comprising a number of quaternary ammonium groups.

Apparatus (100) for the quantification of biological components (3, 3′, 3″) in a fluid comprising: a measurement cell (1) comprising detection electrodes (4, 4′, 5, 5′, 6, 6′, 34, 34′, 84, 84′, 94, 94′, 184, 184′, 194, 194′) and reference electrodes (7, 7,′ 8, 8′, 9, 9′, 37, 37′, 64, 64′, 74, 74′, 164, 164′, 174′); an electronic unit (201) for the generation of input signals, impedimetric measurement, amplification of output signals and communication with a user interface; means for the generation of a magnetic field (101, 102, 103) with an appropriate gradient that can be modulated in time, said means of magnetisation being configured to generate a magnetic field capable of causing, in combination with concentrators (10, 10′, 10″, 14, 14′, 14′, 15) housed in the measurement cell, the separation of the components (3, 3′, 3″) to be quantified from the rest of the solution and their concentration on the detection electrodes (4, 4′, 5, 5′, 6, 6′, 34, 34′, 84, 84′, 94, 94′, 184, 184′, 194, 194′).

The present disclosure relates to a measuring probe for electrochemical measurements, including a probe housing having a first cavity to hold a first electrolyte, a first electrode disposed in the first cavity and contacting the first electrolyte, a first junction disposed in a wall of the probe housing, the junction at least temporarily connecting the first cavity with an environment of the measuring probe, a second cavity formed in the probe housing to hold a second electrolyte, a second electrode disposed in the second cavity and contacting the second electrolyte, and a second junction having reversible open and closed states, in which in the closed state the second junction separates the first cavity and the second cavity and in the open state connects the second cavity to the first cavity, thereby enabling a current flow between the first electrolyte and the second electrolyte, mediated via ions as charge carriers therebetween.

A pH sensor with automatic water storage and replenishment, including a substrate, a working electrode, a reference electrode, a first piezoelectric micropump, a water storage device, and a second piezoelectric micropump. The working electrode, the reference electrode, the first piezoelectric micropump, the water storage device, and the second piezoelectric micropump are arranged on the substrate. The working electrode and the reference electrode are each connected to a bonding pad through an electrode lead. The second piezoelectric micropump, the water storage device, and the first piezoelectric micropump are sequentially communicated, and a liquid flows to the working electrode via an outlet of the first piezoelectric micropump.

An example device includes a processor to connect to an electrode disposed within a microfluidic volume and to connect a second electrode that includes a surface of silver metal disposed within the microfluidic volume. The processor is to apply an electrical potential between the electrode and the second electrode when the microfluidic volume contains a fluid that contains chloride ions to form a layer of silver chloride on the surface of the second electrode. The processor is further to cease application of the electrical potential and operate the second electrode as a reference electrode in a measurement process performed within the microfluidic volume.

A preparation method of indium oxide with stable morphology includes: (1) mixing indium oxide powder and bismuth oxide powder according to a mass ratio of 1:0.1-0.5 to obtain a powder mixture; (2) putting the powder mixture into a ball mill for ball milling at room temperature to obtain a uniform powder mixture; (3) putting the obtained uniform powder mixture into a muffle furnace and calcining at 700-1000° C.; and (4) obtaining the indium oxide with cubic stable morphology after the muffle furnace naturally cools to room temperature. The method has advantages of simple synthesis process, short synthesis period, high sample yield, no need of complicated equipment, and morphology of the obtained indium oxide can be maintained after being heated at a high temperature within 1000° C. for 2 hours. An electrochemical sensor prepared by using the indium oxide obtained by the method has better selectivity to nonane.

A gas sensor includes a pump electrode disposed in a measured gas flow path, an oxygen detection electrode disposed in the measured gas flow path and containing platinum and zirconia, and a reference electrode disposed in a reference gas chamber where a reference gas exists, and containing platinum and zirconia. A first position of a front end of the pump electrode is located closer to a rear end side than a second position of a front end of the oxygen detection electrode is. When the content of zirconia in the oxygen detection electrode is X [%], and a ratio of a distance between the first and second positions to a longitudinal dimension of the pump electrode is Y [%], Y≥141.96e.sup.−0.031X is satisfied. The content of zirconia is not lower than that of platinum in the reference electrode.

This present disclosure is directed to a silver metal wire coated with silver sulfide reference electrode, the preparation via anodization of a silver metal wire in a sodium and/or potassium sulfide solution and use thereof, including test methods to measure corrosion in test articles such as metal pipes. The reference electrode exhibits good stability characteristics, including stability under high temperature conditions.

Disclosed herein are electrochemical-based sensors, comprising: a solid electrode material; a linker moiety bound to the solid electrode material; and a receptor bound to the linker moiety, wherein the receptor binds to a target, and the binding of target to receptor causes an increase in the charge transfer resistance of the solid electrode material. In particular, the present disclosure relates to an electrochemical sensor which is selective for the S.sub.1 subunit of the SARS-CoV-2 spike protein and which uses boron-doped diamond as a solid electrode material. Sensor networks comprising one or more such sensors are also disclosed herein, along with methods of detecting a target (e.g., SARS-CoV-2) using such sensors.

Active biofluid management may be advantageous to the realization of wearable bioanalytical platforms that can autonomously provide frequent, real-time, and accurate measures of biomarkers in epidermally-retrievable biofluids (e.g., sweat). Accordingly, exemplary implementations include a programmable epidermal microfluidic valving system capable of biofluid sampling, routing, and compartmentalization for biomarker analysis. An exemplary system includes a network of individually-addressable microheater-controlled thermo-responsive hydrogel valves, augmented with a pressure regulation mechanism to accommodate pressure built-up, when interfacing sweat glands. The active biofluid control achieved by this system may be harnessed to create unprecedented wearable bioanalytical capabilities at both the sensor level (decoupling the confounding influence of flow rate variability on sensor response) and the system level (facilitating context-based sensor selection/protection). Through integration with a wireless flexible printed circuit board and seamless bilateral communication with consumer electronics (e.g., smartwatch), contextually-relevant (scheduled/on-demand) on-body biomarker data acquisition/display may be achieved.