A device for detecting airborne contaminants includes a protonated, electrically conductive sensing material with affinity for binding with, and capable of being deprotonated by, the airborne contaminant. Electronics measure a property of the sensing material that is sensitive to deprotonation and generates signals indicative of the airborne contaminant. A method for detecting airborne contaminants includes: determining a property change of the protonated, electrically conductive material; and determining presence of the airborne contaminant based on the change. A system for detecting airborne contaminants includes: a data center in remote communication with multiple sensing devices each having: protonated, electrically conductive sensing material with affinity for binding with, and capable of being depronated by, an airborne contaminant, and electronics for relaying signals indicative of a sensing material deprotonation property to the data center; and wherein a user associated with a sensing device is notified of an abnormal level of the airborne contaminant.

Disclosed are sensors that include a carbon nanotube channel and a non-fouling polymer layer, where the non-fouling polymer layer and the carbon nanotube channel do not directly contact each other and are separated by a dielectric layer. The disclosed sensors may be used, e.g., as biosensors for the accurate and sensitive detection of analytes within a sample. Also disclosed are methods of making and using the sensors.

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.

The filter of a gas sensor comprises an inorganic porous support supporting both an organic sulfonic acid compound including sulfo group (—SO3H) and a Lewis acid having at least a metal element of transitional metal elements, Al element, Ga element, In element, Ge element, and Sn element. The Lewis acid loaded in the inorganic porous support adsorbs low concentration siloxanes. The organic sulfonic acid compound including sulfo group polymerizes adsorbed siloxanes in the filter so as not to desorb from the filter.

A sensor for sensing diols and triols includes (a) a substrate, (b) a conductive coating disposed on the substrate and having affinity for binding with a substance selected from the group consisting of diols, triols, and a combination thereof, and (c) two electrodes in contact with the conductive coating to probe conductivity of the conductive coating so as to detect the substance from a reduction in the conductivity. A method for detecting vaping includes (a) measuring conductivity of a conductive coating having affinity for binding with an airborne substance selected from the group consisting of diols, triols, and a combination thereof, and (b) detecting presence of the airborne substance as a decrease in the conductivity.

A method of fabricating a polymer wire according to the present embodiment includes preparing an electrode platform having a micro gap, forming a plurality of single polymer wires on the electrode platform, and a heat treatment operation of aggregating the plurality of single polymer wires to form an aggregated polymer wire.

Methods of detecting a non-explosive analyte can include exposing a sensor compound to a non-explosive analyte and displaying a change in the sensor compound upon exposure of the sensor compound to the non-explosive analyte. A variety of sensor compounds for detecting a target analyte, including both explosive and non-explosive analytes, is also described. Sensor devices for detecting a target analyte can include a substrate and a sensor compound positioned on the substrate in a plurality of detection zones.

A gas sensor includes: a substrate; a first conductor and a second conductor that are disposed on the substrate; an insulating layer; and an adsorbent layer. The insulating layer covers the first conductor and the second conductor, and has a first opening that allows a part of a surface of the first conductor to be exposed therethrough and a second opening that allows a part of a surface of the second conductor to be exposed therethrough. The adsorbent layer contains a conductive material and an organic adsorbent that can adsorb a gas. The adsorbent layer is in contact with the first conductor and the second conductor respectively through the first opening and the second opening.

Described are interdigitated electrodes, which may optionally be plasmonic, useful for in vitro biosensing applications. Such devices may significantly reduce undesired background noise by separating the excitation source (light) from the detection signal (current), and thereby, leading to higher sensitivity for bioanalysis compared with conventional interdigitated electrodes. Also described are methods of making such interdigitated electrodes, which allow a substrate, which may optionally be plasmonic, to be tuned not only to maximize the targeted interaction of the cells with the nanoscale geometry, but also for the excitation wavelength to minimize biological sample interference.

Provided herein are chlorophyll polymers and conductive materials, sensors, and devices comprising the chlorophyll polymers, and methods of use and preparation thereof.