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.

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.

Disclosed are a hydrogen detection sensor and a method of manufacturing the same. The hydrogen detection sensor is manufactured by using hydrothermal synthesis method to synthesize a molybdenum oxide (MoO.sub.3) nanostructure, and irradiating UV light thereon to form an MoO.sub.3Pd nanocomposite comprising the molybdenum oxide nanostructure with palladium (Pd) catalyst particles, and coating the MoO.sub.3Pd nanocomposite on a substrate. As such, a visible color change from the MoO.sub.3 before and after exposure to hydrogen may be so obvious that the sensing or sensitivity of hydrogen and the long-term stability may be substantially improved. In addition, the manufacturing process is simple, and the manufacturing costs may be reduced.

An electrochemical sensor for determining carbon dioxide gas concentration and electrochemical compressor for pumping carbon dioxide are constructed using an anion exchange membrane, catalyst film, and two electrodes. For the sensor, the membrane is compressed between the two electrodes and a voltage reading is output to a computer that then correlates the reading to a carbon dioxide concentration. For the compressor, the membrane is compressed between two plates and current is passed through the plates to pump carbon dioxide through.

A CO.sub.2-sensitive planar sensing device is disclosed, which has an electrode with an ion-selective layer, an electrolyte layer and an outer layer. The electrolyte layer has osmotically active species in an amount of 0.8-6.0 milliosmol per m.sup.2 of electrolyte layer area, and has a hydrophilic osmolarity increasing component which does not add bicarbonate ions or chloride ions to the electrolyte layer.

The invention relates to an electrochemical measuring cell for measuring the content of chlorine compounds in water, having an electrolyte chamber (2) which receives an electrolyte, a measuring electrode (3) which delimits the electrolyte chamber, a reference electrode (5), and a counterelectrode (4). Said electrochemical measuring cell is characterised in that the measuring electrode (3) is a rigid, porous platinum membrane having a pore size of 0.15 m to 0.25 m, which produces the contact with the electrolyte and the water.

An electrode for use in an electrochemical gas sensor for measuring alcohol, a composition for making such an electrode, a process for making an electrode, and an electrochemical gas sensor including such an electrode are provided. The electrode includes a metal adapted and configured to react alcohol and a non-metallic material. The non-metallic material comprises glass, in particular silicon dioxide, silicate, polypropylene and/or polyethylene.

Disclosed is an ammonia sensor element having a measured gas chamber, a reference gas chamber and a solid electrolyte body arranged therebetween. The solid electrolyte body has a first main surface facing the measured gas chamber and a second main surface facing the reference gas chamber. A detection electrode is formed on the first main surface. A reference electrode is formed on the second main surface. The solid electrolyte body contains a first proton conducting solid electrolyte. The detection electrode contains a second proton conducting solid electrolyte. The second proton conducting solid electrolyte has an acid strength greater than that of the first proton conducting solid electrolyte.

A gas detector includes a measurement control section that controls a voltage application section, obtains an output current flowing between a first electrode and a second electrode of an electrochemical cell, and detects a concentration of sulfur oxides in exhaust gas based on the output current. The measurement control section uses a minimum value of the output current obtained by using a current detection section in a period in which lowering sweep is executed and in which an applied voltage is a voltage within a detection voltage range that is equal to or lower than a decomposition initiation voltage of sulfur oxides as a parameter used for detection of the concentration of sulfur oxides.

Provided herein noncovalent hybrids comprising carbon nanotubes (CNTs) and aromatic compounds, composites based on them, process of preparation and uses thereof; wherein the hybrids possess superior mechanical and electrical properties.