Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

Processes, compositions, and sensors for sensing a variety of toxic chemicals based on colorimetric changes. Exemplary process for sensing a toxic chemical includes contacting a toxic chemical, or byproduct thereof, with a sorbent that includes a porous metal hydroxide or a porous mixed-metal oxide/hydroxide and a transition metal reactant suitable to react with a toxic chemical or byproduct thereof. The sorbent is contacted with the toxic chemical or byproduct thereof for a sampling time. A difference between a post-exposure colorimetric state of the sorbent and a pre-exposure colorimetric state of the sorbent is determined to thereby detect exposure to, or the presence of, the toxic chemical or byproduct thereof.

Ultrasensitive, decoupled thermodynamic sensing platforms for the detection of chemical compounds in the vapor phase at trace levels are disclosed, wherein the sensors have a heating resistor decoupled from a sensing resistor. Embodiments of the decoupled sensor comprise a metallic microheater resistor on one side of substrate, and a sensor resistor coupled to a catalyst on the other side of the substrate. A sensor array may be provided including a plurality of sensors each having a different catalyst that, when exposed to an analyte, each experience an endothermic reaction, an exothermic reaction, or no reaction. A comparison of the reaction results to data comprising previously obtained reaction results may be used to determine the presence and the identity of the analyte. Advantageously, the decoupled sensors utilize less power and provide greater sensitivity than other known systems, and may be used to detect and identify a single molecule of an analyte.

The present invention includes an apparatus and method for detecting the location of one or more sources of one or more target molecule, the apparatus comprising: a molecule detector; and a processor connected to the molecule detector and to a global position system, wherein the processor calculates the presence of the one or more target molecules, runs a computer code that determines a dynamic reverse gas stack model for the one or more target molecules, and triangulates the possible position for a source or effluent of the one or more target molecules based on the dynamic reverse gas stack model. The determined reverse gas stack model may have a Gaussian dispersion over one or more sampled locations.

Transparent indicator tape is used for the detection of airborne chemicals in a suspect environment. In various embodiments, the indicator tape is affixed to a window or lens wherein one or more colorimetric indicators clad to the tape are exposed to the environment while humans or detection devices on the other side of the window or lens are not necessarily subjected to the suspect environment. In various embodiments the colorimetric indicator is sensitive to chemical warfare agents. Airborne chemicals including chemical warfare agents may detected by visual review or autonomous measurement of sensor color changes when in the presence of a target chemical. In various embodiments, the an indicator spot is split into sensitive and insensitive regions such that colorimetric changes may be more readily identified against a visually changing background.

An analog matching filter includes a first plate, a second plate coupled with the first plate and separated from the first plate via a spacer, and a replicate matching material fixed to an inside surface of the first plate. A conductive plate or sheet is fixed to an inside surface of the second plate. An electrical circuit connects the first plate to the conductive plate or sheet. The replicate matching material and the conductive plate or sheet generate an opposite polarization pattern carried by the electrical circuit that is based on a polarization pattern of smokeless gunpowder according to a spatial gradient of the smokeless gunpowder local electric field distribution.

A method for reducing the variability, as measured by relative standard deviation (RSD), of an analytical testing technique is provided. This improvement in RSD improves the confidence in the values obtained during field testing. The method includes incorporating a focusing agent into the sampling media, which permits providing sampling media such as thermal desorption tubes preloaded with the focusing agent.

A gas accumulation and combustion control device combining a sorption system, a ventilation system, a control system, and sensor system, with the sensor system configured to detect gas contaminants, transmit a gas detection signal to the control system, the control system configured to adjust the ventilation system based on the gas detection signal, the ventilation system configured to draw the contaminated air in from the atmosphere and lead it toward the sorption system, which in turn is configured to adsorb or absorb the gas contaminants.

A portable fume sensing device. The portable fume sensing device includes a user-proximal end adapted to be held by a user of the portable fume sensing device, a sensing end connected to the user-proximal end by a stem and disposed distally from the user, and a hydrocarbon fume sensor located at the sensing end. A fan is disposed at the sensing end in a user-distal direction from the fume sensor, the fan impelling air towards the fume sensor from a location located in a user-distal direction from the fan. The longitudinal axis of the stem is oriented substantially diagonally with respect to the plane of the fan. An enclosure containing visual indicators, audible indicators, and user operable controls is located at the user-proximal end, the enclosure being coupled to a grip portion that is adapted to be held by a user.

A carbon electrode having a functional moiety that forms a charge-transfer complex with a nitro-containing compound covalently attached to a surface of the electrode, and a process of preparing such an electrode are provided. Also provided are sensing systems integrating the carbon electrode and methods utilizing same for electrochemical detection of nitro-containing compounds.