The techniques relate to methods and apparatus for sensing an analyte. At least one sensor element is configured to sense an analyte, the at least one sensor element comprising a first portion and a second portion. A first current electrode is attached to the first portion and a second current electrode is attached to the second portion. A first measurement electrode is attached to the first portion and a second measurement electrode is attached to the second portion.

An electrolyte-based field effect transistor includes a dielectric layer; a source electrode and a drain electrode located on top of the dielectric layer; the electrolyte-based transistor further including an electrolyte layer between and on top of the source electrode and the drain electrode, the part of the electrolyte layer located between the source electrode and the drain electrode being in direct contact with the dielectric layer; and a gate electrode on top of the electrolyte layer, the orthogonal projection of the gate electrode in a plane including the source and drain electrodes being located, at least in part, between the source and the drain electrodes.

An electrolyte-based field effect transistor includes a dielectric layer; a source electrode and a drain electrode located on top of the dielectric layer; the electrolyte-based transistor further including an electrolyte layer between and on top of the source electrode and the drain electrode, the part of the electrolyte layer located between the source electrode and the drain electrode being in direct contact with the dielectric layer; and a gate electrode on top of the electrolyte layer, the orthogonal projection of the gate electrode in a plane including the source and drain electrodes being located, at least in part, between the source and the drain electrodes.

Provided is an electrical property measuring device capable of increasing reliability of evaluation of electrical properties of 3D structures such as living tissues and biomimetic structures and simplifying a measurement process by improving an ion concentration gradient caused by an ion concentration polarization phenomenon. The electrical property measuring device includes an ion-selective permeable membrane having a porous structure; and a non-uniform microchannel spaced apart from the ion-selective permeable membrane and including a plurality of parallelly arranged flow channels through which a fluid passes, wherein cross-sectional areas of the flow channels are different.

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.

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.

A sensor array includes a plurality of sensors. A sensor of the plurality of sensors has a sensor pad exposed at a surface of the sensor array. A method of treating the sensor array includes exposing at least the sensor pad to a wash solution including sulfonic acid and an organic solvent and rinsing the wash solution from the sensor pad.

In one example, a sensor includes a heterojunction bipolar transistor and component sensing surface coupled to the heterojunction bipolar transistor via an extended base component. In another example, a biosensor for detecting a target analyte includes a heterojunction bipolar transistor and a sensing surface. The heterojunction bipolar transistor includes a semiconductor emitter including an emitter electrode for connecting to an emitter voltage, a semiconductor collector including a collector electrode for connecting to a collector voltage, and a semiconductor base positioned between the semiconductor emitter and the semiconductor collector. The sensing surface is coupled to the semiconductor base of the heterojunction bipolar transistor via an extended base component and includes a conducting film and a reference electrode.

Provided is a charge-transfer-type sensor suitable for high integration while eliminating a potential barrier. A sensor provided with a semiconductor substrate 10 partitioned into a sensing region 5 in which a potential varies in corresponding fashion to a variation in the external environment, a charge input region 2 for supplying charges to the sensing region 5, an input charge control region 3 interposed between the sensing region 5 and the charge input region 2, and a charge accumulation region 7 for accumulating electric charges transported from the sensing region 5, the sensor for detecting the amount of electric charges accumulated in the charge accumulation region 7, wherein a diffusion layer 4 is formed between the input charge control region 3 and the sensing region 5 of the substrate 10, and dopants for producing charges having the same polarity as the charges supplied from the charge input region 2 are diffused in the diffusion layer 4.

Provided is a charge-transfer-type sensor suitable for high integration while eliminating a potential barrier. A sensor provided with a semiconductor substrate 10 partitioned into a sensing region 5 in which a potential varies in corresponding fashion to a variation in the external environment, a charge input region 2 for supplying charges to the sensing region 5, an input charge control region 3 interposed between the sensing region 5 and the charge input region 2, and a charge accumulation region 7 for accumulating electric charges transported from the sensing region 5, the sensor for detecting the amount of electric charges accumulated in the charge accumulation region 7, wherein a diffusion layer 4 is formed between the input charge control region 3 and the sensing region 5 of the substrate 10, and dopants for producing charges having the same polarity as the charges supplied from the charge input region 2 are diffused in the diffusion layer 4.