A field effect gas sensor, for detecting a presence of a gaseous substance in a gas mixture, the field effect gas sensor comprising: a SiC semiconductor structure; an electron insulating layer covering a first portion of the SiC semiconductor structure; a first contact structure at least partly separated from the SiC semiconductor structure by the electron insulating layer; and a second contact structure conductively connected to a second portion of the SiC semiconductor structure, wherein at least one of the electron insulating layer and the first contact structure is configured to interact with the gaseous substance to change an electrical property of the SiC semiconductor structure; and wherein the second contact structure comprises: an ohmic contact layer in direct contact with the second portion of the SiC semiconductor structure; and a barrier layer formed by an electrically conducting mid-transition-metal oxide covering the ohmic contact layer.

In an example, a device for sensing a property of a fluid may include an ion-sensitive field effect transistor (ISFET) having a gate, a source, and a drain. The device may also include a first metal element in contact with the gate and a switching layer in contact with the first metal layer. A resistance state of the switching layer is to be modified through application of an electrical field of at least a predefined strength through the switching layer and is to be retained in the switching layer following removal of the electrical field. The device may also include a metal plate in contact with the switching layer, in which the metal plate is to directly contact the fluid for which the property is to be sensed.

In an example, a device for sensing a property of a fluid may include an ion-sensitive field effect transistor (ISFET) having a gate, a source, and a drain. The device may also include a first metal element in contact with the gate and a switching layer in contact with the first metal layer. A resistance state of the switching layer is to be modified through application of an electrical field of at least a predefined strength through the switching layer and is to be retained in the switching layer following removal of the electrical field. The device may also include a metal plate in contact with the switching layer, in which the metal plate is to directly contact the fluid for which the property is to be sensed.

A pixel circuit acts as a sensing element in a sensing device. The pixel circuit includes a sensing electrode, a first gate electrically connected to the sensing electrode, a second gate in electrical communication with the first gate, and a readout device that is electrically connected to the second gate. An input voltage applied to the sensing electrode is amplified between the first gate and the second gate, the amplification being measured as an output signal from the readout device to perform a sensing operation. For example, the output signal may be relatable to pH, analyte measurements, or other properties of sample liquids analyzed by the sensing device. A sensing device may include multiple pixels disposed on a substrate, each pixel including said pixel circuit. Driver circuits controlled by control electronics are configured to generate signals that selectively address the pixels and to read out voltages at the sensing electrodes.

A pixel circuit acts as a sensing element in a sensing device. The pixel circuit includes a sensing electrode, a first gate electrically connected to the sensing electrode, a second gate in electrical communication with the first gate, and a readout device that is electrically connected to the second gate. An input voltage applied to the sensing electrode is amplified between the first gate and the second gate, the amplification being measured as an output signal from the readout device to perform a sensing operation. For example, the output signal may be relatable to pH, analyte measurements, or other properties of sample liquids analyzed by the sensing device. A sensing device may include multiple pixels disposed on a substrate, each pixel including said pixel circuit. Driver circuits controlled by control electronics are configured to generate signals that selectively address the pixels and to read out voltages at the sensing electrodes.

A sensor comprising a field-effect transistor of a semiconducting material in two-dimensional nanosheets having an interfacial nanoarchitecture comprising a recognition element, a structural element and a polymeric coating, a gate electrode of the transistor being coplanar with a drain electrode and a source electrode of the transistor; a system using the sensor and methods of preparation and use thereof. The disclosed sensor has increased stability and an interfacial nanoarchitecture suitable for the immobilization of a broad number of recognition elements without loss of their biological activity.

The present invention relates to methods for creating conductive nanojunctions using metalized or conductive polymer joined to a DNA nanowire in a nanodevice for chemosensing and biosensing.

A digital microfluidics (DMF) device including an FET-biosensor (FETB) and method of field-effect sensing is closed. In some embodiments, the DMF device may include one or more FETBs integrated into the top substrate, the bottom substrate, or both the top and bottom substrates of the DMF device. In some embodiments, the DMF device may include one or more “drop-in” style FETBs in the top substrate, the bottom substrate, or both the top and bottom substrates of the DMF device. In some embodiments, the DMF device, FETB, and method of field-effect sensing provide active-matrix control integrated into an active-matrix DMF device. Further, a microfluidics system for and method of using the DMF device including at least one FETB is provided.

The invention is directed to apparatus and methods for delivering multiple reagents to, and monitoring, a plurality of analytical reactions carried out on a large-scale array of electronic sensors under minimal noise conditions. In one aspect, the invention provides method of improving signal-to-noise ratios of output signals from the electronic sensors sensing analytes or reaction byproducts by subtracting an average of output signals measured from neighboring sensors where analyte or reaction byproducts are absent. In other aspects, the invention provides an array of electronic sensors integrated with a microwell array for confining analytes and/or particles for analytical reactions and a method for identifying microwells containing analytes and/or particles by passing a sensor-active reagent over the array and correlating sensor response times to the presence or absence of analytes or particles. Such detection of analyte- or particle-containing microwells may be used as a step in additional noise reduction methods.

A ratiometric vapor sensor is described that includes a first sensor and a second sensor. The first sensor includes a first semiconductor component comprising a vapor-sensitive semiconducting organic compound, while the second sensor includes a second semiconductor component comprising a modified vapor-sensitive semiconducting organic compound including a modifying organic group. The ratiometric vapor sensor can be used to detect the presence of a vapor such as nitrogen dioxide, and determine the concentration of the vapor by comparing the outputs of electrodes connected to the first and second sensor.