A method to make metal-organic frameworks (MOFs) in which a first aqueous solution of a transition metal salt is mixed with a second aqueous solution of an imidazole or alkyl-substituted imidazole to yield a product solution containing MOF crystals. The MOF crystals are used to fabricate electrodes for electrochemical detection of nitro-aromatic compounds.

The present disclosure relates to biosensors (10) having a receptor layer (5) and a mediator layer (6), the receptor layer including ethylene receptor molecules. The present disclosure also relates to sensor units (20) comprising one or more biosensors (10) and a controller (11). In some embodiments, one or more sensor units (20) may be in wireless communication with a receiver module or a network gateway.

A system for determining an ambient concentration of compositions for bathroom cleaning comprises a processor operable to receive a concentration measurement from a sensor over a network within a first period of time. The processor is operable to compare the received concentration measurement to a first threshold and to a second threshold greater than the first threshold. The processor is operable to instruct a memory communicatively coupled to the processor to store an indication that a bathroom was cleaned in response to a determination that the received concentration measurement is greater than the first threshold and less than the second threshold. The processor is operable to send an alert for display on a user device indicating either that the sensor has been tampered or that a spill event has occurred in response to a determination that the received concentration measurement is greater than the second threshold.

The first electrochemical oxygen sensor includes: a positive/negative electrode; and an electrolyte solution, the electrochemical oxygen sensor further including: a separation membrane for limiting an amount of oxygen supplied to the positive electrode, and a resistance element for connecting the positive electrode and the negative electrode. In one embodiment, a value of current flowing through the resistance element is 7 μA or more in an atmosphere of 50% relative humidity at 25° C. and 1 atm, and a resistance value of the resistance element is set at 1050 Ω or less. In another embodiment, a value of current flowing through the resistance element is 4 μA or more in an atmosphere of 50% relative humidity at 25° C. and 1 atm, and a resistance value of the resistance element is set so that the output voltage between both ends of the resistance element falls within a range from 4 to 9.5 mV.

The first electrochemical oxygen sensor includes: a positive/negative electrode; and an electrolyte solution, the electrochemical oxygen sensor further including: a separation membrane for limiting an amount of oxygen supplied to the positive electrode, and a resistance element for connecting the positive electrode and the negative electrode. In one embodiment, a value of current flowing through the resistance element is 7 μA or more in an atmosphere of 50% relative humidity at 25° C. and 1 atm, and a resistance value of the resistance element is set at 1050 Ω or less. In another embodiment, a value of current flowing through the resistance element is 4 μA or more in an atmosphere of 50% relative humidity at 25° C. and 1 atm, and a resistance value of the resistance element is set so that the output voltage between both ends of the resistance element falls within a range from 4 to 9.5 mV.

In accordance with an embodiment, a sensing device for sensing an environmental parameter includes a measurement module configured for providing a sequence of measurement values in dependence on the environmental parameter; a communication module configured for communicating with a further sensing device; and a function analysis module coupled to the measurement module and the communication module. The function analysis module configured for using a neural network for determining a first temporal feature on the basis of the sequence of measurement values, and determining, on the basis of the first temporal feature and on the basis of a second temporal feature provided by the further sensing device, information about a functional state of the measurement module.

In an example of a selective, real-time gas sensing method, a gas sample, potentially including a specific gas molecule to be sensed, is supplied to an interface between a working electrode and an ionic liquid electrolyte. Based on at least one unique electrochemical reaction of the specific gas molecule to be sensed, a driving force is implemented to initiate a series of reactions involving the specific gas molecule. In response to the implementation of the driving force, a signal indicative of the specific gas molecule is monitored for.

A gas detection device includes a housing, a top disk, an electrochemical sensor, a gasket, and an electrically resistive material, the top disk, electrochemical sensor, gasket and electrically resistive material are located in the housing and the electrically resistive material is located between the housing and the gasket, between the gasket and the top disk, or dispersed through the gasket.

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.

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.