Methods for using rose bengal for detection of oxidative decomposition of contaminants
Inventors
Owens, Jeffery Ray • McDonald, Rashelle S. • Volkov, Dmytro
Assignees
United States Department of the Air Force
Publication Number
US-9470610-B2
Publication Date
2016-10-18
Expiration Date
2034-10-22
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
Rose Bengal for detecting a presence of and decomposing contaminants. A method of detecting the presence of a contaminant includes treating a substrate with Rose Bengal and exposing the substrate to a light having a wavelength within the visible spectrum. A response of the Rose Bengal is monitored during the light exposure. When a contaminant is present and is exposed to the light, a conversion of the Rose Bengal between a quinoid form and a lactone form is induced.
Core Innovation
The invention relates to the use of Rose Bengal (RB) for detecting and decomposing contaminants on substrates by exploiting RB's unique chemical properties. A substrate treated with Rose Bengal is exposed to visible light, inducing a conversion between the quinoid and lactone forms of Rose Bengal when a contaminant is present, which produces a measurable response. This conversion provides a mechanism to detect the presence of contaminants and monitor their decomposition through changes in colorimetric and fluorescence properties.
The method further includes the decomposition of contaminants via a Rose Bengal induced photocatalytic oxidation mechanism under light exposure, effectively detoxifying contaminated substrates. Rose Bengal can be applied neat, incorporated into coatings, cross-linked to fabrics, polymers, or nanoparticles, enhancing detectability and self-decontamination properties of substrates. Monitoring the fluorescent or absorbance response during light exposure provides real-time feedback on the presence and neutralization state of contaminants.
The problem addressed by the invention is the limitation of conventional chemical warfare agent simulants and pesticide detection and decontamination methods. Existing decontamination assurance sprays indicate contamination by color changes but do not decompose contaminants nor provide information about the effectiveness or completion of decontamination without re-application. Therefore, there is a need for assurance sprays or detection methods that both decompose contaminants and give feedback on contamination removal or neutralization.
Claims Coverage
The patent contains several independent claims focused on methods of detecting contaminants using Rose Bengal treated substrates exposed to visible light, with various configurations of Rose Bengal application and contaminant interactions.
Detection of contaminants by Rose Bengal cross-linked to substrate
A method that involves treating a substrate by cross-linking Rose Bengal to it, exposing the substrate to visible light, and monitoring Rose Bengal’s response, where contaminant presence induces conversion between quinoid and lactone forms.
Use of secondary dyes with Rose Bengal for enhanced detection
A method treating a substrate with Rose Bengal and a secondary dye selected from Rhodamine 560, Rhodamine 640, or both, exposing to visible light, and monitoring Rose Bengal’s conversion to detect contaminants.
Decomposition of contaminants by Rose Bengal photocatalysis
Including in the detection method a step of decomposing contaminants via Rose Bengal induced photocatalytic oxidation under visible light exposure.
Detection of specific chemical warfare agent simulants
Detecting contaminants consisting specifically of Demeton-S, diisopropyl fluorophosphates, or bis(2-chloroethyl) sulfide by treating a substrate with Rose Bengal, exposing to visible light, and monitoring Rose Bengal’s response.
The independent claims collectively cover methods of applying Rose Bengal to substrates or nanoparticles, optionally with secondary dyes, exposing to visible light, monitoring the induced conversion of Rose Bengal to detect contaminants, and decomposing contaminants via Rose Bengal photocatalytic oxidation, including specific chemical warfare agent simulants.
Stated Advantages
Rose Bengal exhibits strong fluorescence and absorbance responses to contaminants, allowing effective detection and monitoring.
In the presence of visible light, Rose Bengal efficiently decomposes contaminants through a photocatalytic oxidation mechanism.
Rose Bengal is non-toxic, commercially available, relatively inexpensive, and FDA approved, making it practical for various applications.
The invention provides both detection of contaminants and real-time monitoring of decontamination effectiveness, unlike conventional sprays that only indicate presence.
Documented Applications
Detection and decomposition of chemical warfare agent simulants and pesticides on substrates or assets.
Incorporation of Rose Bengal into coatings, fabrics, polymers, or nanoparticles for contamination detection and self-decontamination.
Use in decontamination assurance sprays providing feedback on contaminant neutralization.
Cross-linking Rose Bengal into silica nanoparticles which are applied to cotton fibers to detect chemical agent simulants such as Demeton-S, diisopropyl fluorophosphates, and bis(2-chloroethyl)sulfide.
Interested in licensing this patent?