Abstract: A gas sensor apparatus (100) comprising a gas inlet (10); a first gas sensor (40); a first gas flow path between the inlet and the gas sensor; a humidifier (20) disposed between the gas inlet and the gas sensor in the first gas flow path of the gas sensor apparatus; and a dehumidifier (30) disposed between the humidifier and the first gas sensor in the first gas flow path. The gas sensor apparatus may have more than one gas flow path. The gas sensor apparatus may contain more than one sensor. The gas sensor apparatus may contain one or more filters for filtering a target gas or a non-target gas. The gas sensor apparatus may be used in detection of ethylene and/or 1-methylcyclopropene.

Abstract: A gas sensor system for measuring a plurality of gases in an environment. The gas sensors system comprises multiple gas sensors where each of the gas sensors includes a pair of electrodes separated by a semiconducting material. The gas pairs of electrodes of the gas sensors are separated by different distances in each of the gas sensors. Resistivity of the semiconducting material of the gas sensors changes in the presence of a first gas and a contact resistivity between the electrodes and the semiconducting material of gas sensors changes in the presence of a second gas. From measurements of total resistivity of each of the gas sensors the presence and/or the concentration of both the first and the second gas sensors can be determined.

Abstract: Method of sensing A method of sensing a target material in an environment is disclosed. The method comprises exposing a sensor to an environment for a first exposure period. The method further comprises, following the first exposure period, isolating the sensor from any target material in the environment for a first isolation period wherein the first isolation period is less than a characteristic recovery period for the sensor to return to a baseline after the first exposure period. The method further comprises, following the first isolation period, exposing the sensor to the environment for a second exposure period, and determining a concentration of the target material from a response of the sensor during the second exposure or a response of the sensor during the first and second exposure.

Abstract: A gas sensor apparatus (100) comprising a gas inlet (10); a first gas sensor (40); a first gas flow path between the inlet and the gas sensor; a humidifier (20) disposed between the gas inlet and the gas sensor in the first gas flow path of the gas sensor apparatus; and a dehumidifier (30) disposed between the humidifier and the first gas sensor in the first gas flow path. The gas sensor apparatus may have more than one gas flow path. The gas sensor apparatus may contain more than one sensor. The gas sensor apparatus may contain one or more filters for filtering a target gas or a non-target gas. The gas sensor apparatus may be used in detection of ethylene and/or 1-methylcyclopropene.

Abstract: An apparatus for determining a presence, a concentration or a change in concentration of a target material in an environment is disclosed. The apparatus comprises first and second sensors configured to respond to the target material. The apparatus further comprises a fluid inlet in fluid communication with the environment, and a valve assembly having a first and second configuration. In the first configuration, the fluid inlet is in fluid communication with only the first sensor. In the second configuration, the fluid inlet is in fluid communication with the first sensor and the second sensor.

Abstract: A method of sensing a target gas in an environment in which a response of a semiconducting gas sensor device upon exposure to the environment is measured. The semiconducting gas sensor device includes first and second electrodes in electrical contact with a doped organic semiconductor layer and is, e.g., an organic thin film transistor or organic chemiresistor. The measured response may be indicative of a cumulative amount of a target gas that the semiconducting gas sensor device has been exposed to. A gas sensor module containing the semiconducting gas sensor device may be connectable to a reader configured to read the semiconducting gas sensor device after exposure to the environment. The connection may be wired or wireless. The target gas may be 1-methylcyclopropene.

Abstract: A method of determining a presence, concentration or change in concentration of a first or second material in an environment is disclosed. The method comprises measuring a response of a first sensor to the first and second material, wherein the first sensor is one of a metal oxide sensor, an electrochemical sensor, a photoionisation sensor, an infrared sensor, a pellistor sensor, an optical particle monitor, a quartz crystal microbalance sensor, a surface acoustic wave sensor, a cavity ring-down spectroscopy sensor, or a biosensor. The method further comprises measuring a response of a second sensor to the first and second material, wherein the second sensor is another one of a metal oxide sensor, an electrochemical sensor, a photoionisation sensor, an infrared sensor, a pellistor sensor, an optical particle monitor, a quartz crystal microbalance sensor, a surface acoustic wave sensor, a cavity ring-down spectroscopy sensor, a biosensor or a field effect transistor sensor.

Abstract: A fluorescent infrared emitting composition comprising a mixture of a first material and a second material wherein the first material is a fluorescent infrared material and the second material is a fluorescent material having a higher photoluminescent quantum yield (PLQY) and shorter peak wavelength than the infrared emitting material. The composition may be used as the light-emitting layer of an organic light-emitting device.

Abstract: A sensor system that removes responses from an interferent and/or corrects for baseline drift of a sensor to determine a presence, a concentration or a change in concentration of a target material in a gaseous environment. Fluid flowing into the system may be directed by a valve arrangement to either a first fluid flow path or a second fluid flow path. The target material may be absorbed by a filter material in the first fluid flow path. Fluid flowing along the second gas flow path passes directly to the sensor. Responses of the sensor to fluids from the first and second fluid flow paths may be used to determine a presence, concentration or change in concentration of the target material.

Abstract: A gas sensor system (100) for detecting conjugated hydrocarbons and/or esters in an environment. The gas sensor system includes two organic thin film transistor (OTFT) gas sensors (200, 300). The first OTFT gas sensor (200) allows for interaction of the conjugated hydrocarbon with the gas sensor's source and drain electrodes, and the second OTFT gas sensor (300) blocks the conjugated hydrocarbon from interacting with the gas sensor's source and drain electrodes. In the second gas sensor, a monolayer comprising 4-aminobenzenethiol and 4-fluorobenzenethiol may cover the source and drain electrodes preventing the conjugated hydrocarbon from interacting with the source and drain electrodes. The gas sensor system may be used to monitor a volatile conjugated hydrocarbon and/or an ester produced by fruit.

Abstract: An apparatus for determining a presence, a concentration or a change in concentration of a target material in an environment is disclosed. The apparatus comprises first and second sensors configured to respond to the target material. The apparatus further comprises a fluid inlet in fluid communication with the environment, and a valve assembly having a first and second configuration. In the first configuration, the fluid inlet is in fluid communication with only the first sensor. In the second configuration, the fluid inlet is in fluid communication with the first sensor and the second sensor.

Abstract: A gas sensor system for measuring a plurality of gases in an environment. The gas sensors system comprises multiple gas sensors where each of the gas sensors includes a pair of electrodes separated by a semiconducting material. The gas pairs of electrodes of the gas sensors are separated by different distances in each of the gas sensors. Resistivity of the semiconducting material of the gas sensors changes in the presence of a first gas and a contact resistivity between the electrodes and the semiconducting material of gas sensors changes in the presence of a second gas. From measurements of total resistivity of each of the gas sensors the presence and/or the concentration of both the first and the second gas sensors can be determined.

Abstract: A top gate thin film transistor gas sensor for detecting or measuring a concentration of a target gas. The gas sensor is configured so that the target gas can pass through the top gate and interact with a semiconducting layer of the gas sensor. The top gate may not cover a channel of the semiconducting layer disposed beneath the top gate so that the target gas may communicate with the channel without impedance by the top gate. The top gate may be patterned with channels through which the target gas may pass through the top gate to the channel in the semiconducting layer. The top gate may be permeable to the target gas allowing passage of the target gas to the channel. A substrate on which the semiconducting layer is formed may be permeable to the target gas allowing the target gas to communicate with the channel.

Abstract: A method of sensing a target gas in an environment in which a response of a semiconducting gas sensor device upon exposure to the environment is measured. The semiconducting gas sensor device includes first and second electrodes in electrical contact with a doped organic semiconductor layer and is, e.g., an organic thin film transistor or organic chemiresistor. The measured response may be indicative of a cumulative amount of a target gas that the semiconducting gas sensor device has been exposed to. A gas sensor module containing the semiconducting gas sensor device may be connectable to a reader configured to read the semiconducting gas sensor device after exposure to the environment. The connection may be wired or wireless. The target gas may be 1-methylcyclopropene.

Abstract: A fluorescent infrared emitting composition comprising a mixture of a first material and a second material wherein the first material is a fluorescent infrared material and the second material is a fluorescent material having a higher photoluminescent quantum yield (PLQY) and shorter peak wavelength than the infrared emitting material. The composition may be used as the light-emitting layer of an organic light-emitting device.

Abstract: A gas sensor system is made up of a first gas sensor that is sensitive to both a target gas (200) and a secondary gas and a second sensor (300) that is only sensitive to the target gas. The response of the two gas sensors is processed to detect a presence of or a concentration of the target gas. The first sensor includes a semiconductor material that is sensitive to the presence of both the target and the secondary gas and electrodes that are sensitive to the presence of the target gas. The second sensor includes a semiconductor material that is sensitive to the presence of both the target and the secondary gas, but also includes a blocking layer on a surface of at least one of the electrodes that prevents the second gas interacting with the electrodes.

Abstract: A sensor for detecting and measuring a gas in a gaseous environment where the gaseous environment contains an interferent such as a related gas. A vertical chemiresistor with a top gate includes a semiconductor layer that has a bulk resistivity that changes in the presence of the gas and/or the interferent. The electrodes (103, 107) of the vertical chemiresistor have a work function that changes when the gas is absorbed onto the electrode. This absorption changes the work function of the electrode and thereby the contact resistance of the electrode in the vertical chemiresistor. By detecting changes in the contact resistance and the bulk resistivity of the semiconducting layer (105) the presence and the concentration of the gas may be determined and distinguished from the interferent.

Abstract: A thin film transistor gas sensor and a method of sensing a target gas using the thin-film transistor gas sensor. A gate electrode of the thin film transistor gas sensor has a conductive layer with a surface in direct contact with a dielectric layer of the thin-film transistor. The work function at the surface changes when it comes into contact with a target gas, for example the gate electrode may be formed from gold and have a surface work function that changes when the surface of the gold gate electrode comes into contact with a gas, such as 1-methylcyclopropene.

Abstract: We describe a method for reducing a parasitic resistance at an interface between a conducting electrode region and an organic semiconductor in a thin film transistor, the method comprising: providing a solution comprising a dopant for doping said semiconductor, and depositing said solution onto said semiconductor and/or said conducting electrode region to selectively dope said semiconductor adjacent said interface between said conducting electrode region and said semiconductor, wherein depositing said solution comprises inkjet-printing said solution.

Abstract: Provided is a solution comprising a polymer and an organic semiconductor compound, wherein the semiconductor compound is a thiophene derivative, and wherein the solvent is a mixture comprising a) at least one of 4-methyl anisole, indane and an alkylbenzene with a linear or branched alkyl group containing from 4 to 7 carbon atoms; and b) at least one of tetrahydronaphthalin and 1,2,4-trimethylbenzene.