Analyte sensors and methods for fabricating analyte sensors are provided. In an exemplary embodiment, a method for fabricating a planar flexible analyte sensor includes sputtering platinum onto a polyester base layer to form a layer of platinum. The method includes patterning the layer of platinum to form working electrodes and additional electrodes. Further, the method includes forming an insulating dielectric layer over the base layer, wherein the insulating dielectric layer is formed with openings exposing portions of the working electrodes and portions of the additional electrodes. Also, the method includes partially singulating individual sensors from the base layer, wherein each individual sensor is connected to the base layer by a tab. The method further includes depositing an enzyme layer over the exposed portions of the working electrodes and coating the working electrodes with a glucose limiting membrane.

Analyte sensors and methods for fabricating analyte sensors in a roll-to-roll process are provided. In an exemplary embodiment, a method includes providing a roll of a polyester substrate having a first side coated with a layer of platinum, wherein the platinum is in direct contact with the polyester substrate; patterning the layer of platinum to form electrodes; punching the polyester substrate to form ribbons, wherein each ribbon is connected to a remaining polyester substrate web by a tab, and wherein each sensor includes an electrode; after punching the polyester substrate to form ribbons, depositing an enzyme layer over the portions of the working electrodes and coating the working electrodes with a glucose limiting membrane; after depositing the enzyme layer over the portions of the working electrodes and coating the working electrodes with a glucose limiting membrane, singulating the individual sensors by completely separating each individual sensor from the polyester substrate.

An electrochemical ion sensor and a method for sensing a presence of at least one ion species in a solution are provided. The electrochemical sensor includes a solid-state electrolyte medium doped with an organometallic material, having an electrochemical affinity with the ion species, and a pair of electrodes electrically contacting the solid-state electrolyte. The electrochemical sensor also includes an electrical circuit configured to drive the pair of electrodes with an AC electrical excitation and to measure at least one parameter related to a complex electrical impedance of the doped solid-state electrolyte medium in response to the AC electrical excitation. The parameter may be an electrical resistance, an inductance or a combination of both, and represents the presence of the ion species in the solution when the solid-state electrolyte medium is exposed to the solution.

An immersion sensor is configured to determine the content of a chemical element in molten metal. The immersion sensor has an auxiliary electrochemical cell extending from an interior surface into the internal volume of a sampling chamber. The sampling chamber can be integrally-formed in a sensor head or in a separate refractory structure. The immersion sensor may be configured for the flow of molten metal into the internal volume of the sampling chamber and into contact with the auxiliary electrochemical cell.

An immersion sensor is configured to determine the content of a chemical element in molten metal. The immersion sensor has an auxiliary electrochemical cell extending from an interior surface into the internal volume of a sampling chamber. The sampling chamber can be integrally-formed in a sensor head or in a separate refractory structure. The immersion sensor may be configured for the flow of molten metal into the internal volume of the sampling chamber and into contact with the auxiliary electrochemical cell.

A device for measuring pH levels and contaminant concentration includes an electrode assembly that is electrically coupled to a control unit. The electrode assembly includes a FLUID first contact electrically coupled to a reference electrode, a second contact electrically coupled to a working electrode, and a third contact electrically coupled to a counter electrode. The working electrode may be modified to include a cysteine functionalized graphene oxide with polypyrrole nanocomposite. In operation, the control unit may apply a complex signal to the working electrode via the second contact in order to adhere and subsequently strip contaminant ions from the fluid sample to the working electrode. During this process, a current may be measured across the reference electrode and the counter electrode to measure contaminant ion concentration. The pH of the fluid sample may also be determined by a current measured across the reference electrode and the counter electrode. In some examples, the pH may be used to calibrate the measured levels of the contaminant ions.

A sensor for the detection of lead includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode. The working electrode includes a metalized film with working surface and a monolayer (or bilayer) of bismuth deposited on the working surface by underpotential deposition.

A sensor for the detection of lead includes a substrate, a working electrode formed on a surface of the substrate, a counter electrode formed on the surface of the substrate, a dielectric layer covering a portion of the working electrode and counter electrode and defining an aperture exposing other portions of the working electrode and counter electrode. The working electrode includes a metalized film with working surface and a monolayer (or bilayer) of bismuth deposited on the working surface by underpotential deposition.

A potentiometric oxygen sensor for measuring the oxygen concentration of a liquid metal, including: a metal tube forming at least one sensor body part; an electrochemical subassembly containing an electrolyte, intended to be in contact with the liquid metal, and a reference electrode contained in the electrolyte, the electrolyte being made of yttrium-doped or calcium-doped hafnia (HfO.sub.2), or of thoria (ThO.sub.2), which is optionally yttrium-doped or calcium-doped, or of yttrium-doped or calcium-doped zirconia (ZrO.sub.2), the reference electrode containing at least one metal and its oxide form at the operating temperature of the sensor, an insert made of a transition metal from group 4 of the Periodic Table or an alloy thereof, arranged between the sensor body part and the electrolyte, the insert being attached to the sensor body part and brazed onto the electrolyte by a brazing joint.

A gel for use in a pH or an ORP sensor, components of the gel comprising water, a reference electrolyte salt, a buffering system for adjusting pH of the gel, and a polymeric gelling agent, and the gel does not degrade under gamma irradiation.