A sensor element includes an element body, an upper connector electrode disposed on a first surface of the element body, and a protective layer that covers at least a front end-side part of the first surface. The protective layer includes a first specific protective layer having a thickness T1 of 10 μm or less. The ratio T1/T2 of the thickness T1 to the thickness T2 of a front-side portion of the protective layer which faces the front end of the first specific protective layer is 1.0 or less.

A sensor element includes: an element base made of an oxygen-ion conductive solid electrolyte; an internal space provided inside the element base; an electrochemical pump cell configured to pump oxygen in and out between the internal space and outside; a porous thermal shock resistant layer provided to an outermost peripheral part in a predetermined range at one end part of the element base, at which a gas inlet is provided; and a buffer layer adjacent to the thermal shock resistant layer on a pump surface and a heater surface. A thermal diffusion time in a thickness direction of the thermal shock resistant layer is 0.4 sec to 1.0 sec inclusive, and a total thermal diffusion time in a stacking direction of the thermal shock resistant layer and the buffer layer is 0.2 sec to 1.0 sec inclusive.

A sensor element includes an element base made of an oxygen-ion conductive solid electrolyte, an internal space provided inside the element base, an electrochemical pump cell that pumps oxygen in and out between the internal space and outside, and a porous thermal shock resistant layer provided to an outermost peripheral part in a predetermined range at one end part of the element base, at which a gas inlet is provided. A thermal diffusion time in a thickness direction of the thermal shock resistant layer is 0.4 sec to 1.0 sec inclusive. A thermal diffusion time at a leading end part of the thermal shock resistant layer covering the gas inlet at a farthest leading end position at the one end part is longest, and a thermal diffusion time at a pump surface is longer than a thermal diffusion time at a heater surface.

A hydrogen sensor that efficiently detects hydrogen gas at room temperature comprising a gold decorated reduced graphene oxide/zinc oxide (Au/rGO/ZnO) heterostructured composite, methods for making this sensor and a method for sensitive room temperature detection of hydrogen using the sensor.

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.

Flexible fuel cell sensors and methods of making and using the same are provided. A fuel cell sensor can be used for the detection of, for example, isopropyl alcohol (IPA), and the working mechanism of the fuel cell sensor can rely on redox reactions. The fuel cell sensor can include a proton exchange membrane (PEM), an anode disposed on a first surface of the PEM, a cathode disposed on a second surface of the PEM opposite from the first surface, and a reference electrode disposed on the first surface of the PEM and spaced apart from the anode.

There is presented an electrochemical sensor (100) for sensing an analyte in an associated volume (106), the sensor comprising a first solid element (126), a second solid element (128) being joined to the first solid element, a chamber (110) being placed at least partially between the first solid element and the second solid element, a working electrode (104) in the chamber (110), a reference electrode (108), and wherein one or more analyte permeable openings (122) connect the chamber (110) with the associated volume (106), and wherein the electrochemical sensor (100) further comprises an analyte permeable membrane (124) in said one or more analyte permeable openings, wherein the one or more analyte permeable openings are placed at least partially between the first solid element and the second solid element.

Provided are: an electrode for a gas sensor formed as a porous electrode so as to stably allow reduction in electrode resistance for excellent low-temperature activity; and a gas sensor. The electrode (108, 110) for the gas sensor is adapted for use on a surface of a solid electrolyte body (109), which is predominantly formed of zirconia, and contains particles (2) of a noble metal or an alloy thereof, first ceramic particles (4) of stabilized zirconia or partially stabilized zirconia and second ceramic particles (6) of one or more selected from the group consisting of Al.sub.2O.sub.3, MgO, La.sub.2O.sub.3, spinel, zircon, mullite and cordierite, wherein the second ceramic particles are contained in an amount smaller than that of the first ceramic particles.

A gas sensor includes a sensor element having electrode pads, metal terminal members connected to the respective electrode pads, separators, and lead wires connected to the rear ends of the metal terminal members. Each metal terminal member has a forward locking portion and a rear locking portion provided at the forward and rear ends, respectively. The separator is composed of a forward separator and a rear separator connected to each other. The forward separator includes a first locking portion having a rearward-facing surface, and the rear separator includes a second locking portion having a forward-facing surface. The metal terminal member is held between the forward separator and the rear separator in a state in which the forward locking portion is in locking engagement with the rearward-facing surface and the rear locking portion is in locking engagement with the forward-facing surface.

A mixed-potential type gas sensor capable of preferably determining the concentration of THC including a kind of gas having a large C number is provided. A sensor element composed of an oxygen-ion conductive solid electrolyte is provided with, on its surface, a sensing electrode formed of a cermet of Pt, Au, and an oxygen-ion conductive solid electrolyte, and includes a reference electrode and a porous surface protective layer that covers at least said sensing electrode. An Au abundance ratio on a surface of noble metal particles forming the sensing electrode is 0.3 or more. The surface protective layer has a porosity of 28% to 40%, a thickness of 10 to 50 μm, and an area ratio of a coarse pore having a pore size of 1 μm or larger of 50% or more; or has a porosity of 28% to 40% and a thickness of 10 to 35 μm.