The present disclosure relates to a novel composite film configured for CO.sub.2 sensing, and the method of making and using the novel composite film. The novel composite film comprises a carbon nanotube film and a CO.sub.2 absorbing layer deposited on the carbon nanotube film, wherein the CO.sub.2 absorbing layer comprises a mixture of a branched polyethylenimine, a polyethylene glycol, and poly[1-(4-vinylbenzyl)-3-methylimidazolium tetrafluoroborate] of formula I: ##STR00001## wherein n ranges from 10-300.

Provided are a chemiresistor and a method of manufacturing the same, a chemiresistive sensor, and a device. The chemiresistor includes a conductive porous nanocomposite of a three-dimensional metal-organic framework and a two-dimensional metal-organic framework, wherein the two-dimensional metal-organic framework is chemically bound to the three-dimensional metal-organic framework on a surface of the three-dimensional metal-organic framework, and the three-dimensional metal-organic framework and the two-dimensional metal-organic framework form a core-shell structure in the conductive porous nanocomposite.

A sensor device. The sensor device includes a sterilant-responsive switch comprising: a circuit; a conductive polymer having a first state and a second state, and a polymeric binder; and wherein the sterilant-responsive switch connects the circuit in the first state and disconnects the circuit in the second state, and wherein the conductive polymer is capable of being converted from being in the first state to being in the second state when in contact with a sterilant.

A low-cost and low-power polyaniline-based (PANI) gas sensor is provided. The PANI-based gas sensor is formed on a flexible polyimide (PI) substrate using additive manufacturing techniques. The gas sensor can include silver interdigitated electrode (IDE) arrays and conducting polymeric sensing films (i.e., PANI) that are printed onto the PI substrate using a direct-write technology of aerosol-jet printing. Aerosol-jet printing enables high-resolution, non-contact deposition of both the electrode and chemically sensitive materials. The gas sensor is optionally capable of 5 ppm sensitivity and a sub-ppm detection limit.

The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor and a preparation method thereof, belonging to the technical field of biosensors. The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor, including a substrate, an electrode layer, a graphene film, and a three-dimensional hydrogel material layer that are stacked in sequence; where the three-dimensional hydrogel material layer is formed of a hydrogel material having a three-dimensional network structure; the hydrogel material is obtained by polymerization of raw materials including an acrylamide monomer and a modified probe molecule; and the modified probe molecule is a probe molecule modified with an acrylamide group. The three-dimensional hydrogel-graphene-based biosensor has a desirable stability and a high sensitivity.

According to various embodiments, there is provided an odor sensor including at least two sensor elements each having a substance adsorbing membrane for adsorbing one or more odor substances included in air; and an electrical signal conversion unit for measuring the electrical characteristics of the substance adsorbing membrane after adsorption of the substance, in which the substance adsorbing membrane has a main skeleton containing an electroconductive polymer and contains a dopant for modifying the main skeleton of the electroconductive polymer, and the at least two sensor elements are respectively provided with substance adsorbing membranes having different proportions of the main skeleton and the dopant. Also provided is an odor measurement system using the sensor.

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.

In an embodiment, the present disclosure pertains to a method of sensing an analyte in a sample by: (1) exposing the sample to an electrode that includes a covalent-organic framework with a plurality of metal-coordinated aromatic units that are linked to one another by aromatic linkers; (2) detecting a change in a property of the electrode; and (3) correlating the change in the property to the presence or absence of the analyte. In an additional embodiment, the present disclosure pertains to said covalent-organic frameworks. Additional embodiments of the present disclosure pertain to methods of making the covalent-organic frameworks.

Provided are a chemiresistive sensor module, a wireless electronic device, and an IoT system. The chemiresistive sensor module includes a chemiresistive sensor including a composite material of a three-dimensional metal-organic framework and a two-dimensional metal-organic framework, a measuring unit for measuring a data on change in electrical resistance detected from the chemiresistive sensor and electrically connected to the chemiresistive sensor, and a communication unit for transmitting the data on change in electrical resistance to an external device.

A sensor device for sensing CO.sub.2 comprises a hybrid sensing material and a transducer. The hybrid sensing material comprises at least amines and nanoparticles, wherein the hybrid sensing material has a property and is configured to change the property dependent on a current CO.sub.2 concentration in the surrounding. The transducer is configured to output an electrical sensor signal dependent on the property of the hybrid sensing material.