An electrochemical gas sensor device with small physical footprint is disclosed. The electrodes within the element are arranged about the electrolyte such that the electrical impedance of the sensor is minimized. This results in a fast stabilization after detecting gasses and enables rapid changes in bias voltage to target different gasses. Gasketing elements, or alternative designs, are included to eliminate the diffusion of gasses between the electrodes within the cell.

An electrochemical sensor device that is efficiently and economically produced at the chip level for a variety of applications is disclosed. In some aspects, the device is made on or using a wafer technology whereby a sensor chamber is created by said wafer and a gas port allows for a working electrode of the sensor to detect certain gases. Large scale production is possible using wafer technology where individual sensors are produced from one or more common wafers. Integrated circuits are made in or on the wafers in an integrated way so that the wafers provide the substrate for the integrated circuitry and interconnects as well as providing the definition of the chambers in which the gas sensors are disposed.

Embodiments of the invention are directed to a system for detecting neurotransmitters. A non-limiting example of the system includes a porous electrode. A system can also include a pH sensor attached to the porous electrode, wherein the pH sensor includes a sensing electrode and a reference electrode. The system can also include electronic circuitry in communication with the pH sensor.

The present invention discloses a novel capacitive vapor sensor comprising porous immobilized graphene oxide (pGO) on an electrode surface. Also disclosed is an in-situ process for the preparation of this sensor and various uses thereof.

A sensor element includes: an element body including an oxygen-ion-conductive solid electrolyte layer; and a protective layer that covers at least part of the element body and is a porous body having a plurality of pores thereinside. The standard deviation of the porosity of the protective layer is 2.3% or less.

An electrochemical oxygen sensor according to the present invention includes a positive electrode, a negative electrode, and an electrolyte solution constituted by an aqueous solution, in which the negative electrode includes a metal containing, as a main component, an element M selected from Sn and Ni, the electrolyte solution is an aqueous solution having a pH of 3 to 10, the positive electrode includes a catalyst layer containing a catalytic metal, and the catalyst layer includes, on a surface that is in contact with the electrolyte solution, a surface layer containing the element M.

A method of sensing a target gas in an environment in which a response of a semiconducting gas sensor device upon exposure to the environment is measured. The semiconducting gas sensor device includes first and second electrodes in electrical contact with a doped organic semiconductor layer and is, e.g., an organic thin film transistor or organic chemiresistor. The measured response may be indicative of a cumulative amount of a target gas that the semiconducting gas sensor device has been exposed to. A gas sensor module containing the semiconducting gas sensor device may be connectable to a reader configured to read the semiconducting gas sensor device after exposure to the environment. The connection may be wired or wireless. The target gas may be 1-methylcyclopropene.

In an embodiment, a hydrogen monitoring system comprises a plurality of sensing elements that individually comprise a working electrode, a counter electrode, an insulating layer located in between the working electrode and the counter electrode, a catalyst located on an end of both the working electrode and the counter electrode, an electrolyte located on the end of the sensing elements on both the working electrode and the counter electrode, between the working electrode and the counter electrode, and in contact with the catalyst, and an electrical circuit located on an opposite end of the sensing element that connects the working electrode and the counter electrode.

A method of operating a gas detection device including a capillary-limited, electrochemical gas sensor includes operating the gas sensor in a sensing mode during which a signal from the gas sensor is representative of a concentration of the analyte gas measured by the gas sensor and in an interrogation mode during which the gas sensor is electronically interrogated by applying an electric signal to the gas sensor to generate a non-faradaic current flow between a working electrode and a counter electrode without the application of a test gas, periodically entering the interrogation mode, measuring a parameter of a gas sensor output during the interrogation mode, comparing the measured parameter to one or more previously measured parameters, determining an operational state from the comparison, and returning the gas sensor to the sensing mode if the operational state is determined to be within a predetermined range.

An improvement in the method or technique of conditioning a gas sensor is provided through the application of Pulse Discharge Technique (PDT) in order to condition mixed-potential gas sensors. A modified planar sensor design to minimize sodium atom diffusion and platinum electrode poisoning under conditions of PDT are provided. Modification of the PDT hardware is provided without modification of the sensor design. The improvement method comprises: a) Replace a single polarity power supply with a power supply with floating positive and negative output; b) Connect one of the heater leads with the reference electrode lead and connect it to the ground.