To be provided is a metal paste from which an electrode having high electrode activity as a sensor electrode of various gas sensors can be produced. The present invention is a metal paste for forming a gas sensor electrode obtained by dispersing a conductive particle including Pt or a Pt alloy and a ceramic powder including zirconia or stabilized zirconia, or any of zirconia and stabilized zirconia and one or more oxides of La, Ce, Pr, Nd, Sm, and Hf in a solvent, the metal paste further including an inorganic oxide particle containing alumina and an insoluble particle that is insoluble in the solvent, in which 0.5 or more to 3.0 mass % or less of the inorganic oxide particle and 1.0 to 5.0 mass % of the insoluble particle are dispersed based on the mass of the solid content of the conductive particle, the ceramic powder, the inorganic oxide particle, and the insoluble particle.

An ion exchange membrane separated two electrode flow analyzer for continuous aqueous electrochemical heavy metal detection is disclosed. The electrochemical cell includes a gas diffusion counter/reference electrode, a flooded flow through working electrode, and an ion exchange membrane that separates the gas diffusion counter/reference electrode and the flooded flow through working electrode. A method of continuous fluid analysis using a multi-electrode flow analyzer is also disclosed, including passing an aqueous sample through a first inlet flow area and into a working electrode of a multi-electrode flow analyzer, passing a gas mixture through a second inlet flow area and into a counter/reference electrode of the multi-electrode flow analyzer, depositing an analyte onto a surface of the working electrode, stripping the analyte from the surface of the working electrode by sweeping a range of a potential applied to the surface of the working electrode.

A method of exposing a sample to an electrical effect for electrochemical analysis of the sample in an electrolyte solution is disclosed. The method comprises causing an external electrical conductor of an electrode head to apply the electrical effect, the external electrical conductor of the electrode head being external to the electrode head and on an external side of the sample exposed to the electrolyte solution. Apparatuses are also disclosed.

An electrochemical sensor is provided which may be formed using micromachining techniques commonly used in the manufacture of integrated circuits. This is achieved by forming microcapillaries in a silicon substrate and forming an opening in an insulating layer to allow environmental gases to reach through to the top side of the substrate. A porous electrode is printed on the top side of the insulating layer such that the electrode is formed in the opening in the insulating layer. The sensor also comprises at least one additional electrode. The electrolyte is then formed on top of the electrodes. A cap is formed over the electrodes and electrolyte. This arrangement may easily be produced using micromachining techniques.

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.

A method of making an array of aligned hafnium oxide nanotubes is provided. The method includes generating a first reactant gas from a first solution comprising a first hafnium precursor dissolved in a first solvent. Directing the flow of the first reactant gas over a substrate to form a seed layer that comprises particles of hafnium oxide. The method further includes generating a second reactant gas from a second solution comprising a second hafnium precursor dissolved in a second solvent. Directing the flow of the second reactant gas over the seed layer to form the array of aligned hafnium oxide nanotubes substantially perpendicular on a surface of the substrate. A method of using the array of aligned hafnium oxide tubes for detection of toxic gases in a gas sample is also provided.

Provided is a fluid-permeable electrode having an open-cell structure and having: a layer of an electroactive material deposited on a surface of an open cell substrate that is formed of a material that differs from the electroactive material; or a fluid-permeable electrode having an open-cell structure and consisting of an electroactive material.

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.

We provide an electrochemical sensor in which working microelectrodes are arranged in an array and interconnected in parallel. The working electrodes are arranged so that in use, they are electrochemically coupled to a counter electrode structure through an electrolyte. The sensor also includes a microporous body arranged so that in use, it is situated at a boundary between a gaseous environment and the electrolyte. In another aspect, we provide a method of sensing in which a sample of gas is admitted to a liquid electrolyte maintained by pores of a porous substrate. A voltage is applied to the liquid electrolyte, and an electrical response to the applied voltage is observed, thereby to detect electrochemical evidence of an analyte within the liquid electrolyte.

Apparatus and associated methods relate to a compact gas sensor (CGS) including a housing with a central stepped cavity with one or more first lead contact(s) forming a portion of a base plane in a bottom of the cavity and one or more second lead contact(s) forming a portion of a stepped plane higher than the base plane, the cavity sized to receive a chemically based stack of material made up of a bottom diffusion electrode layer, a middle electrolyte gel layer, and a top diffusion electrode layer. The bottom diffusion electrode layer is in electrical contact with the first lead contact(s). The top diffusion electrode layer electrically couples to the second lead contact(s) via an overlaying micro electromechanical system (MEMS) element layer with conductive coating. In an illustrative example, the CGS may provide gas sensing in small spaces.