Sensor and method for rapid in situ detection of toxic gases
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Publication Number
US-12066419-B1
Publication Date
2024-08-20
Expiration Date
Abstract
A sensor and method for the rapid detection of fluoride containing gaseous species specifically the chemical warfare agents Sarin and Soman nerve gas, in which a chemically sensitive composition containing dye indicator molecules complexed with a heavy metal salt is exposed to an environment under surveillance for toxic gasses. In one embodiment the sensing composition is introduced into a polymer-based substrate. The detection composition reacts with hydrogen fluoride which is a decomposition by-product of Sarin and Soman gas so as to change the color of the dye indicator, in one embodiment being pentamethoxy red, that is to change the color of the polymer-based substrate from colorless to a dark purple color. The complex of pentamethoxy red with the exemplary heavy metal salt, zirconyl chloride, is specific for Sarin and Soman nerve gas; it does not react to certain other toxic gases. In various embodiments a hydrolyzing agent is introduced in the polymer-based substrate to improve the detection reaction sensitivity and to increase the reaction rate and decrease the detection time for sensor chemistry.
Core Innovation
A chemical sensor is disclosed that uses a polymer-based substrate permeable to a predefined target chemical substance. The polymer-based substrate includes an embedded chemical indicator whose optical properties change when exposed to the predefined target chemical substance, causing a parametric change of light passing through the polymer-based substrate. The embedded chemical indicator comprises an indicator dye complexed with a heavy metal salt that renders the indicator dye inactive until cleavage is triggered by fluoride.
The indicator dye is rendered inactive by complexation with a heavy metal salt that is functional to be cleaved by a fluoride ion from hydrogen fluoride preferentially to complex with the fluoride ion, thereby activating the dye for dye reaction. In addition, a hydrolyzing agent is embedded in the polymer-based substrate, and the disclosure includes dye activation and a detectable dye coloration indicative of hydrogen fluoride presence.
The disclosed approach is applied to detecting a target chemical for which hydrolyzed fluoride ion is a decomposition by-product, where hydrogen fluoride is monitored through changes in dye coloration. The method provides a polymer-based substrate permeable to the predefined target chemical substance with an indicator dye having an available hydroxyl group rendered inactive by being complexed with the heavy metal salt complex, and with the hydrolyzing agent embedded in the polymer-based substrate.
Claims Coverage
The document contains two independent claims, covering a chemical sensor architecture and a method of detecting a target chemical using a polymer-based substrate with an HF-driven dye activation mechanism. Across the independent claims, the disclosure is centered on a polymer-based substrate with an embedded indicator dye/metal-salt complex and an embedded hydrolyzing agent, with detection by changes in optical properties and dye coloration driven by hydrogen fluoride decomposition by-product and preferential cleavage by fluoride.
Polymer-based substrate with embedded indicator dye-metal-salt complex
A polymer-based substrate permeable to a predefined target chemical substance, the polymer-based substrate comprising an embedded chemical indicator, wherein the optical properties of the polymer-based substrate change when exposed to the predefined target chemical substance causing a parametric change of light passing through the polymer-based substrate, and wherein the embedded chemical indicator comprises an indicator dye complexed with a heavy metal salt, whereby the indicator dye is rendered inactive and which heavy metal salt is preferentially functional to complex with a fluoride ion by cleaving from the indicator dye.
Embedded hydrolyzing agent in polymer-based substrate
A chemical sensor wherein a hydrolyzing agent is embedded in the polymer-based substrate.
Method exposing HF-decomposition environment to cleavable dye complex
Providing a polymer-based substrate permeable to a predefined target chemical substance, the polymer-based substrate comprising an indicator dye having an available hydroxyl group rendered inactive by being complexed with a heavy metal salt which is functional to be cleaved by a fluoride from hydrogen fluoride preferentially to complex with the fluoride ion whereby the dye is rendered active for dye reaction, wherein a hydrolyzing agent is embedded in the polymer-based substrate; exposing the complex to an environment that is under surveillance for the target chemical of which hydrogen fluoride is a decomposition by-product; detecting changes in the dye coloration indicative of the presence of hydrogen fluoride.
Overall claim coverage focuses on a polymer-based substrate permeable to a target chemical with optical-property change caused by an embedded indicator dye/metal-salt complex that is cleaved and activated by hydrogen fluoride-derived fluoride, and on a surveillance method that exposes this polymer-based substrate to an environment where hydrogen fluoride is a decomposition by-product and detects dye coloration indicative of hydrogen fluoride, with an embedded hydrolyzing agent supporting the disclosed dye activation behavior.
Stated Advantages
Provides a detectable optical parametric change of light passing through the polymer-based substrate upon exposure to the predefined target chemical substance.
Renders the indicator dye inactive until preferential functional cleavage by fluoride from hydrogen fluoride activates dye reaction.
Enables detection by detecting changes in dye coloration indicative of the presence of hydrogen fluoride.
Supports surveillance of environments for target chemicals whose hydrogen fluoride is a decomposition by-product.
Documented Applications
Detecting toxic gases by detecting fluoride-containing gaseous species, including Sarin (GB) and Soman (GD), through their decomposition by-product hydrogen fluoride (HF) using dye coloration changes.
Detecting a target chemical whose hydrolyzed fluoride ion is a decomposition by-product by monitoring hydrogen fluoride presence via dye coloration indicative of hydrogen fluoride.
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