Abstract: Closed-loop systems and methods for controlling pH. The system includes a working electrode, a counter electrode, a reference electrode, a first ion-sensitive field-effect transistor (ISFET), a second ISFET, and an electronic controller. The working electrode, the counter electrode, the reference electrode, and a first sensing terminal of the first ISFET are immersible in an active solution. A second sensing terminal of the second ISFET is immersible in a reference solution. The electronic controller is configured to apply a first amount of current or voltage to the working electrode and determine a differential voltage between the first ISFET and the second ISFET. The electronic controller is also configured to set a second amount of current or voltage to reduce a difference between the differential voltage and a target voltage. The electronic controller is further configured to apply the second amount of current or voltage to the working electrode.

Abstract: Electrochemical sensors useful for detection of heavy metals are described. The electrochemical sensors can be made by forming a layer of graphene oxide on a working electrode, forming a layer of carbon nanotubes (CNTs) on the layer of graphene oxide, and forming a layer of gold nanostars on the layer of CNTs.

Abstract: Multi-use biosensors are disclosed that include enzymes coupled to nanobeads; the multi-use biosensors are used to detect analytes in fluidic biological samples, and the biosensors also maintain their enzyme activity after many uses. Multi-sensor arrays are disclosed that include multiple biosensors. Also disclosed are methods of producing and using these devices.

Abstract: A biosensor, including a modified gold electrode and a macrophage RAW264.7 immobilized on the modified gold electrode. The disclosure also provides a method of preparing the biosensor and a method of using the same for evaluation of antioxidant capacity of substances.

Abstract: The present disclosure relates to a cell potential detection device, a method of manufacturing the cell potential detection device, and an information processing system that enable prevention of culture solution for a cell from leaking. The cell potential detection device includes: a cell potential detection chip including an electrode unit that detects potential of a cell; a substrate on which the cell potential detection chip is implemented; a first member sealing a connection electrically connecting the cell potential detection chip and the substrate; and a second member layered on the first member, the second member forming a liquid-storage portion that stores culture solution for the cell, together with the first member. The present technology can be applied to, for example, a semiconductor module in which packaged is a chip that detects the potential at an action-potential source point due to a chemical change of a cell.

Abstract: Reference electrodes that include a solid electron conductor; an interlayer; and a polymeric membrane layer comprising a polymer composition, the polymer composition comprising at least one silicone-containing polymer and at least one ionic liquid, wherein the polymeric membrane layer and the polymer composition are essentially plasticizer free and the silicone-containing polymer and the ionic liquid are miscible as determined using a thermodynamic method that shows a single glass transition temperature (Tg) of a composition including the at least one silicone-containing polymer and the at least one ionic liquid, wherein the interlayer is disposed between the solid electron conductor and the polymeric membrane layer. Also disclosed are electrochemical measurement systems including such reference electrodes.

Abstract: Various cell analysis systems of the present teachings can measure the electrical and metabolic activity of single, living cells with subcellular addressability and simultaneous data acquisition for between about 10 cells to about 500,000 cells in a single analysis. Various sensor array devices of the present teachings can have sensor arrays with between 20 million to 660 million ChemFET sensors built into a massively paralleled array and can provide for simultaneous measurement of cells with data acquisition rates in the kilohertz (kHz) range. As various ChemFET sensor arrays of the present teachings can detect chemical analytes as well detect changes in cell membrane potential, various cell analysis systems of the present teachings also provide for the controlled chemical and electrical interrogation of cells.

Abstract: A surface modified electrode is provided. The surface modified electrode includes a glassy carbon electrode (GCE) and a nanomaterial disposed on the glassy carbon electrode. The nanomaterial comprises carbon nanotubes (CNTs), and at least one of thallium oxide nanoparticles (Tl2O3.NPs), thallium oxide (Tl2O3) nanopowder, and thallium oxide carbon nanotube nanocomposites (Tl2O3.CNT NCs). A polymer matrix is configured to bind the glassy carbon electrode with the nanomaterial. A method of preparing the surface modified electrode is also disclosed. The surface modified electrode can be implemented in a biosensor for detecting a biological molecule, like choline.

Abstract: Methods and apparatuses for selective monitoring of multiple silicon compounds in etchant solutions are provided. Methods can include reacting a test solution comprising a plurality of different silicon compounds with a fluoride-based compound in several conditions to provide different silicon:reagent binding ratios. One of the conditions can include the addition of a co-solvent to the test solution. Concentrations of the multiple silicon compounds can be determined based on the different binding ratios of silicon:reagent. Methods can further include a measuring method such as silicon elemental analysis or measuring of functional groups of a certain silicon form of a first portion of a test solution comprising a plurality of different silicon compounds and reacting a second portion of the solution with a fluoride-based compound to provide a silicon:reagent binding ratio. Concentrations of the multiple silicon compounds can be determined based on the measuring method and binding ratio measurements.

Abstract: An elution apparatus and a detection apparatus are described. The elution apparatus includes: a sample trap for trapping a sample; and one or more pumps and/or valves to move a liquid eluent and a liquid eluate, wherein the eluate includes an extracted portion of the sample that is extracted by the eluent. The detection apparatus includes: a capillary having a low-voltage (LV) end portion to receive a sample; and a conductivity detector coupled to a high-voltage (HV) end portion of the capillary to generate signals based on conductivity of a monitored portion of the capillary in the HV end portion, wherein the conductivity detector is electrically isolated from the LV end portion.

Abstract: Various embodiments disclose an electronic circuit for an electrochemical gas sensor. The electronic circuit comprises a first switching element electrically coupled to a reference terminal of the electrochemical gas sensor and a ground voltage terminal. Further, the electronic circuit comprises a second switching element electrically coupled to a sensing terminal of the electrochemical gas sensor and the ground voltage terminal. In an instance in which the electrochemical gas sensor is powered OFF, the first switching element and the second switching element are configured to electrically couple the reference terminal and the sensing terminal to the ground voltage terminal such that current generated when the sensing electrode and the target gas react while the electrochemical gas sensor is powered OFF flows to the ground voltage terminal and the potential of the reference terminal and the sensing terminal remain the equal.

Abstract: A sensor element includes an element body including an oxygen-ion-conductive solid electrolyte layer, the element body having a longitudinal direction, a measurement electrode disposed in the element body, a reference electrode disposed in the element body so as to come into contact with a reference gas, and a heater configured to heat the solid electrolyte layer. A center of gravity of the reference electrode overlaps the measurement electrode as viewed in a thickness direction of the solid electrolyte layer. A length of each of the reference electrode and the measurement electrode in a front-rear direction is less than or equal to 1.1 mm, the front-rear direction being a direction along the longitudinal direction of the element body. An area of the reference electrode as viewed in the thickness direction is greater than or equal to 1.0 mm2.

Abstract: The invention provides a solid state reference electrode comprising a reference element embedded in an electrochemically active composite, the electrochemically active composite comprising a polymeric matrix loaded with a solid inorganic salt, wherein the polymeric matrix comprises a cross-linked vinyl polymer of a vinyl monomer containing a heteroatom.

Abstract: Electrochemical sensors include a housing within which an electrolyte is provided over the electrodes. The housing includes an active region, which is the area around the electrodes in which the electrolyte must be positioned to ensure correct operation of the device. The inner walls, base and ceiling of the housing are coated in either hydrophobic or hydrophilic materials, or both, so as to encourage the electrolyte to take a position over the active region, which is defined by the position of the electrodes. In some electrochemical sensors, a combination of hydrophobic and hydrophilic materials is used and the materials can be arranged in a pattern, which encourages the electrolyte to take a position over the active region.

Abstract: A biosensor for measuring an electrical response from a biological sample. The biosensor includes a substrate, a passivation layer grown on a surface of the substrate, a patterned catalyst layer deposited on the passivation layer, and three electrodes grown on the patterned catalyst layer. The three electrodes include a working electrode, a counter electrode, and a reference electrode. The working electrode includes a first array of electrically conductive biocompatible nanostructures that is configured to be an attachment site for the biological sample. The counter electrode includes a second array of electrically conductive biocompatible nanostructures that is configured to acquire the electrical response from the working electrode. The reference electrode includes a third array of electrically conductive biocompatible nanostructures that is configured to adjust a specific voltage around the working and the counter electrodes.

Abstract: A method of detecting a lipid bilayer formed in a cell of a nanopore based sequencing chip is disclosed. An integrating capacitor is coupled with a lipid membrane, wherein the lipid membrane is between a working electrode and a counter electrode. An alternating current (AC) voltage is applied to the counter electrode. A voltage across the integrating capacitor is periodically sampled by an analog-to-digital converter (ADC). A change in the sampled voltage across the integrating capacitor in response to a change in the AC voltage is determined. Whether the lipid membrane comprises a lipid bilayer is detected based on the determined change in the sampled voltage across the integrating capacitor in response to the change in the AC voltage.

Abstract: Provided is an electrode for electrochemical measurement for detecting or quantitatively determining a target substance, the electrode comprising: a complex supported on a surface of the electrode, wherein the complex is a complex comprising a probe for the target substance, a quantum dot which binds to the probe and is doped with nitrogen and sulfur, and a conductive polymer nanowire in which a metal nanoparticle is embedded.

Abstract: An electrochemical detection electrode includes: a plurality of electrode structures; and a plurality of groups of detection structures on the plurality of electrode structures; wherein: the plurality of groups of detection structures include a first group of detection structures and a second group of detection structures, each of the first group of detection structures on one of the plurality of electrode structures having a first shape in a plane parallel to a surface of one of the plurality of electrode structures is configured to combine with a first detection object, each of the second group of detection structures on one of the plurality of electrode structures having a second shape in a plane parallel to a surface of one of the plurality of electrode structures is configured to combine with a second detection object; and wherein the first shape is different from the second shape.

Abstract: To provide a sensor device and a measurement apparatus that are able to appropriately control a temperature of a sensing region where a potential is measured. Provided is a sensor device that includes an electrode array exposed to a sensing region, at least one or more wiring line layers provided in a layer same as the electrode array, a temperature determiner that determines a temperature of the sensing region on the basis of an electric resistance of the wiring line layer, and a temperature controller that controls the temperature of the sensing region on the basis of the temperature of the sensing region determined by the temperature determiner.

Abstract: Systems and methods are disclosed for performing event timing detection for DNA sequencing. In certain embodiments, a method may comprise generating a signal based on a DNA strand passed through a nanopore sensor, sampling the signal to generate a plurality of sample values, and detecting one or more event boundaries based on the sample values, an event representing a movement of a single DNA base of the DNA strand through the nanopore sensor. Detecting the one or more event boundaries may include segmenting the plurality of sample values into multiple events to calculate an optimal total score, assigning an event value to a selected event from the multiple events based on sample values of the selected event, and providing the event value to a base caller to determine a sequence of DNA bases.