WO2025042635A2

WO2025042635A2 - Compositions and methods for colorimetric detection of target particles

Info

Publication number: WO2025042635A2
Application number: PCT/US2024/042108
Authority: WO
Inventors: Catherine Lynn Riddle; Ricky Lynn Demmer
Original assignee: Codeac Solutions, Inc.
Priority date: 2023-08-18
Filing date: 2024-08-13
Publication date: 2025-02-27
Also published as: WO2025042635A3

Abstract

Compositions, systems, and methods are provided for detecting target particles, such as target actinide particles. The composition includes 2‑(5‑Bromo‑2‑pyridylazo)‑5‑(diethylamino)phenol (Br‑PADAP), 1‑(2‑Pyridylazo)‑2‑naphthol (PAN), and iron in effective amounts such that on a condition that the composition is in contact with the target actinide particle, a colorimetric output is produced.

Description

COMPOSITIONS AND METHODS FOR COLORIMETRIC DETECTION OF TARGET PARTICLES

Cross-Reference to Related Applications

[0001] This application claims priority to and the filing date benefit of U.S. Provisional Patent Application No. 63/533,401, entitled “Compositions and Methods for Colorimetric Detection of Target Particles,” filed August 18, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Government Interest

[0002] The United States Government has rights in this invention pursuant to Strategic Partnership Project Agreement No. 23SP811 between Battelle Energy Alliance, LLC (Operating Under Contract No. DE-AC07-05ID14517 for the U. S. Department of Energy) and CoDeAc Solutions, Inc.

Background

[0003] The embodiments described herein relate to the detection of target particles, and more specifically to compositions and methods for colorimetric detection of contaminants such as actinides, transition metals, or radioactive elements.

[0004] Exposure to particles of certain elements can be harmful to the exposed. Accordingly, it is often desirable to detect the presence of such particles. For example, in a large-scale nuclear incident, a radiological dispersal device, an improvised nuclear device, or a radiological accident harmful actinides, such as uranium (U) and/or plutonium (Pu), can be dispersed throughout the environment. One of the first steps in responding to the nuclear incident will be to ascertain the size of the contaminated area so that a response perimeter can be established. As part of the response to the nuclear incident, it will often be desirable to decontaminate exposed people, animals, equipment, structures and/or other surfaces. As such, responding personnel must identify individuals, animals, equipment, structures and/or other surfaces that are contaminated by the presence of the harmful actinide particles. However, the response to the nuclear incident can be hampered by an insufficient quantity of nuclei specific radiation detection equipment. Often incident responders use basic kits to search for unknown materials. Such kits are limited and very basic; not designed to identify specific substances, especially radionuclides. Moreover, much of the contamination from U and Pu species is alpha contamination, which is often very difficult to detect. For example, the shielding effects from environmental factors, such as dust, limit the detectability of U and Pu via some conventional radiological detection methods. Similarly, known radiometric grab-sample approaches for actinides are also limited since sampled material requires days of radiochemical separations in a laboratory setting, which is a great disadvantage over a rapid onsite chemical detection kit.

[0005] In addition to a large-scale nuclear incident, in some instances single individuals or small groups can be potentially contaminated with particles of certain elements. For example, in certain industrial, power generation, and/or medical facilities, personnel that perform tasks in or near the facilities can be accidentally exposed to harmful actinide particles without their knowledge. In such instances, early detection of the contamination can be beneficial. Accordingly, frequent, routine screening of personnel whose activities present a contamination risk may be desirable. In order to provide routine screening, it is desirable that the radiological tests provide nearly instantaneous results, on-site, and at a cost that is sustainable for frequent screenings.

[0006] Some known methods for colorimetric detection can be difficult to interpret due to variations in the perceived color when viewed in varying ambient conditions, due to fading of the color over time, or because the color produced may vary depending on the amount of the target particles present. Additionally, the presence of certain elements can interfere with producing reliable and repeatable colorimetric outputs. For example, some known compositions for producing colorimetric output to detect uranium have been identified as being subject to undesirable interference when in the presence of certain elements, such as cadmium, cobalt, copper, iron, manganese, nickel, or zinc.

[0007] Thus, a need exists for new and improved compositions and methods for colorimetric detection of target particles, such as actinides. Summary

[0008] This summary introduces certain aspects of the embodiments described herein to provide a basic understanding. This summary is not an extensive overview of the inventive subject matter, and it is not intended to identify key or critical elements or to delineate the scope of the inventive subject matter.

[0009] In some embodiments, the present disclosure is directed to a composition for detection of a target particle. The composition includes an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN), and an effective amount of iron. On a condition that the composition is in contact with the target particle, a colorimetric output is produced.

[0010] In some embodiments, the target particle is an actinide.

[0011] In some embodiments, the composition is a solution. A ratio of the effective amount of Br-PADAP in the solution and the effective amount of PAN in the solution is between 1 :1 and 3: 1. Additionally, a ratio of the effective amount of iron in the solution and the effective amount of PAN in the solution is between 1 :20 and 1 :50.

[0012] In some embodiments, the composition is a solution. The effective amount of Br-PADAP in the solution is in a range of 1X10’³M and 1X10’⁵M. The effective amount of PAN in the solution is in a range of 1X10‘³M and 1X10'⁶M. The effective amount of iron in the solution is in a range of 1X10'⁵M and 1X10'⁷M.

[0013] In some embodiments, the composition is a solution; and the iron is a soluble ferrous iron.

[0014] In some embodiments, the composition is a solution; and the iron is insoluble ferrous iron.

[0015] In some embodiments, the iron is one of iron (II) nitrate or iron (II) chloride.

[0016] In some embodiments, the target particle is one of uranium, plutonium, or americium. [0017] In some embodiments, the target particle is uranium, and the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers. The identifying absorbance spike portion has a wavelength that is associated with the uranium in contact with the composition.

[0018] In some embodiments, the colorimetric output is a visible shade of purple under a white light on a condition that the composition is in contact with uranium.

[0019] In some embodiments, the colorimetric output is produced at a concentration of 100 parts-per-billion or greater on a condition that the uranium is in a target particle solution.

[0020] In some embodiments, the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xlO'⁶ grams of the uranium.

[0021] In some embodiments, the target particle is plutonium, and the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers. The identifying absorbance spike portion has a wavelength that is associated with the plutonium in contact with the composition.

[0022] In some embodiments, the colorimetric output is a visible shade of peach under a white light on a condition that the composition is in contact with the plutonium.

[0023] In some embodiments, the colorimetric output is produced at a concentration of 1 part-per-million or greater on a condition that the plutonium is in a target particle solution.

[0024] In some embodiments, the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xlO'⁶ grams of the plutonium.

[0025] In some embodiments, the target particle is americium, and the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers. The identifying absorbance spike portion has a wavelength that is associated with the americium in contact with the composition.

[0026] In some embodiments, the colorimetric output is a visible shade of orange under a white light condition on a condition that the composition is in contact with the americium.

[0027] In some embodiments, the colorimetric output is produced at a concentration of 1 part-per-million or greater on a condition that the americium is in a target particle solution.

[0028] In some embodiments, the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xlO'⁶ grams of the americium.

[0029] In some embodiments, the composition is formulated to detect a set of different target particles. The colorimetric output is characterized by a first identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers. The first identifying absorbance spike portion has a wavelength that is associated with the first target particle. The colorimetric output is characterized by a second identifying absorbance spike portion in response to the incident light. The second identifying absorbance spike portion has a wavelength that is associated with a second target particle.

[0030] In some embodiments, the colorimetric output is maintained for at least 24 hours.

[0031] In some embodiments, the colorimetric output is produced within 1 minute after the composition is in contact with the target particle.

[0032] In some embodiments, the composition is a dry powder composition that is formulated to dissolve in an aqueous solvent.

[0033] In some embodiments, the composition includes an effective amount of a masking agent. The masking agent is configured to block an effect of at least one interference substance on the production of the colorimetric output.

[0034] In some embodiments, the present disclosure is directed to a composition for detection of a target actinide particle. The composition includes 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), l-(2-Pyridylazo)-2-naphthol (PAN), and iron in effective amounts such that on a condition that the composition is in contact with the target actinide particle, a colorimetric output is produced.

[0035] In some embodiments, the present disclosure is directed to a kit for the detection of a target particle. The kit includes a container that has a delivery member. A detection solution is within the container. The detection solution includes effective amounts of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), l-(2-Pyridylazo)-2-naphthol (PAN), and iron. The kit also includes a collection member having a detection surface for contacting an object. The detection surface is configured to retain the target particle following contact with the object. The delivery member is configured to convey a portion of the detection solution onto the detection surface. On a condition that the detection solution is in contact with the target particle, a colorimetric output is produced on the detection surface.

[0036] In some embodiments, the target particle is uranium, and the colorimetric output is a visible shade of purple on the detection surface.

[0037] In some embodiments, the uranium is present on the detection surface at a concentration of at least 0.022 g/m².

[0038] In some embodiments, the target particle is plutonium, and the colorimetric output is a visible shade of peach on the detection surface.

[0039] In some embodiments, in some embodiments, the plutonium is present on the detection surface at a concentration of at least 0.023 g/m².

[0040] In some embodiments, the target particle is americium, and the colorimetric output is a visible shade of orange on the detection surface.

[0041] In some embodiments, the americium is present on the detection surface at a concentration of at least 0.023 g/m². [0042] In some embodiments, the detection solution includes an effective amount of a masking agent, the masking agent being configured to block an effect of at least one interference substance on the production of the colorimetric output.

[0043] In some embodiments, the collection member is an electrostatic cloth having a negative charge.

[0044] In some embodiments, the collection member is a swab premoistened with deionized water.

[0045] In some embodiments, the kit includes a second container containing deionized water, and the collection member is a dry swab configured to receive the portion of deionized water prior to contact with the object.

[0046] In some embodiments, the collection member is a swab premoistened with a portion of the detection solution.

[0047] In some embodiments, the collection member is a dry swab configured to receive a portion of the detection solution prior to contact with the object.

[0048] In some embodiments, the delivery member is a spray apparatus configured to atomize a portion of the detection solution for conveyance onto the detection surface.

[0049] In some embodiments, the delivery member is a spray apparatus configured to atomize a portion of the detection solution for conveyance onto the object. The portion of the detection solution is conveyed onto the detection surface via the contacting of the detection surface with the object.

[0050] In some embodiments, the delivery member is a dosing portion that is configured to dispense a specified portion of the detection solution. The dosing portion is formed such that an amount of the detection solution in excess of the specified portion is returned to the container.

[0051] In some embodiments, the kit includes a preservation container configured to receive the collection member following contact with the object. The preservation container including an observation portion positioned to facilitate observation of the colorimetric output on the detection surface.

[0052] In some embodiments, the present disclosure is directed to a method for the detection of a target particle. The method includes contacting an object with a collection member to transfer the target particle from the object to a detection surface of the collection member. The method also includes applying a detection solution to a detection surface of the collection member. The detection solution comprises an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN), and an effective amount of iron. On a condition that the detection solution is in contact with the target particle, a colorimetric output is produced on the detection surface.

[0053] In some embodiments, contacting the object with the collection member includes contacting the object via moving at least a portion of detection surface relative to the object between a first position and a second position.

[0054] In some embodiments, the method includes detecting a visible shade of purple on the detection surface on a condition that the target particle is uranium, detecting a visible shade of peach on the detection surface on a condition that the target particle is plutonium, and detecting a visible shade of orange on the detection surface on a condition that the target particle is americium.

[0055] In some embodiments, the method includes exposing the detection surface to an incident light having a wavelength between about 100 nanometers and about 900 nanometers following the application of the detection solution. The method also includes identifying the target particle based at least in part on an identifying absorbance spike portion produced in response to the incident light. The identifying absorbance spike portion has a wavelength associated with one of uranium, plutonium, or americium.

[0056] In some embodiments, the target particle is a first target particle and the identifying spike portion is a first identifying absorbance spike portion. Additionally, the method includes determining the first target particle based at least in part on the first absorbance identifying spike portion, and determining a second target particle based at least in part on a second identifying absorbance spike portion. The second identifying absorbance spike portion is different from the first identifying absorbance spike portion.

[0057] In some embodiments, the method includes removing the collection member from a hermetically sealed package, the collection member being a swab premoistened with deionized water.

[0058] In some embodiments, the method includes applying a portion of deionized water to a dry swab prior to contact with the object.

[0059] In some embodiments, the method includes removing the collection member from a hermetically sealed package, the collection member being a swab premoistened with a portion of the detection solution.

[0060] In some embodiments, applying the detection solution to the detection surface of the collection member includes depositing a portion of the detection solution on the detection surface via a spray apparatus following the contacting of the object with the collection member.

[0061] In some embodiments, applying the detection solution to the detection surface of the collection member includes depositing a portion of the detection solution on the detection surface via a dosing portion of a solution container following the contacting of the object with the collection member. The dosing portion is configured to dispense a specified portion of the detection solution. The dosing portion is formed such that an amount of the detection solution in excess of the specified portion is returned to the solution container.

[0062] In some embodiments, the method includes placing the collection member within a preservation container following contact with the object. Observing the colorimetric output on the detection surface is performed via an observation portion of the preservation container. Brief Description of the Drawings

[0063] FIG. l is a schematic illustration of a kit for the detection of a target particle, according to an embodiment.

[0064] FIG. 2 is a schematic depiction of a portion of a method for using the kit of FIG. 1 to detect the target particle, according to an embodiment.

[0065] FIG. 3 is a schematic depiction of a portion of a method for using the kit of FIG. 1 to detect the target particle, according to an embodiment.

[0066] FIG. 4 is a schematic depiction of a portion of a method for using the kit of FIG. 1 to detect the target particle, according to an embodiment.

[0067] FIG. 5A is a photograph of a colorimetric output produced by a composition for the detection of the target particle in the absence of a target particle, according to an embodiment.

[0068] FIG. 5B is a photograph of a colorimetric output produced by the composition of FIG. 5A in contact with uranium, according to an embodiment.

[0069] FIG. 5C is a photograph of a colorimetric output produced by the composition of FIG. 5A in contact with plutonium, according to an embodiment.

[0070] FIG. 5D is a photograph of a colorimetric output produced by the composition of FIG. 5A in contact with americium, according to an embodiment.

[0071] FIG. 6A is a depiction of the structure of a first component of the composition of FIG. 5A.

[0072] FIG. 6B is a depiction of the structure of a second component of the composition of FIG. 5A. [0073] FIG. 7 is a plot showing the absorbance (as a function of wavelength) of a colorimetric output in response to exposure to an incident light on a condition that the composition of FIG. 5 A is in contact with the target particle, according to an embodiment.

[0074] FIG. 8 is a plot showing the absorbance (as a function of wavelength) of a colorimetric output in response to exposure to an incident light on a condition that the composition of FIG. 5 A is in contact with a first target particle and a second target particle, according to an embodiment.

[0075] FIG. 9 is a photograph with a first composition (left) having an absence of iron and the composition of FIG. 5A (right) in contact with the same concentration of uranium in solution, according to an embodiment.

[0076] FIG. 10 depicts a use of an algorithm to quantify a colorimetric output of the first composition of FIG. 9, according to an embodiment.

[0077] FIG. 11 depicts a use of the algorithm to quantify a colorimetric output of the second composition of FIG. 9, according to an embodiment.

[0078] FIG. 12 is a flow chart of a method for detecting a target particle, according to an embodiment.

Detailed Description

[0079] Generally, the present disclosure is directed to compositions, testing kits, and methods for the detection of a target particle, such as an actinide. The composition facilitates the rapid detection of the presence of a target particle via producing colorimetric changes that can be easily detected or read by a user. Specifically, the colorimetric outputs produced by the compositions, kits and methods described herein can be visually read and interpreted (e.g., when viewed in ambient light conditions) and can also be read by an instrument that employs spectroscopy techniques. For example, in some embodiments, the compositions, kits and methods described herein can produce a colorimetric output that is characterized by an absorbance spectrum that has a spike (or peak) associated with the target particle. Moreover, the compositions, kits and methods described herein can be used to detect multiple different target particles (e.g., uranium and plutonium) by producing different colorimetric outputs for the different target particles. In this manner, the compositions, kits, and methods described herein facilitate detection of a number of different target particles.

[0080] In some embodiments, the compositions, kits and methods described herein can accommodate detection in the presence of various potentially interfering elements, for example, but including a masking agent. Moreover, the compositions described herein include iron, the presence of which was previously thought disrupt the desired colorimetric output to the point that a determination of the presence of the target particle (e.g., uranium) could no longer be made in confidence. However, it has been discovered that, contrary to the previous teachings, the inclusion of iron in the composition described herein facilitates the desired colorimetric change (or output). In other words, the presence of iron in the composition disclosed herein results in a colorimetric change that is more easily discernible than the colorimetric change (or output) that may result from a composition having an absence of iron. Accordingly, the inclusion of a quantity of iron in the composition increases the ability to detect the target particle.

[0081] As used herein, the term “about” when used in connection with a referenced numeric indication means the referenced numeric indication plus or minus up to 10 percent of that referenced numeric indication. For example, the language “about 50” covers the range of 45 to 55. Similarly, the language “about 5” covers the range of 4.5 to 5.5.

[0082] Further, specific words chosen to describe one or more embodiments and optional elements or features are not intended to limit the invention. For example, spatially relative terms — such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like — may be used to describe the relationship of one element or feature to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e., translational placements) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Likewise, descriptions of movement along (translation) and around (rotation) various axes include various spatial device positions and orientations.

[0083] In addition, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context indicates otherwise. The terms “comprises”, “includes”, “has”, and the like specify the presence of stated features, steps, operations, elements, components, etc. but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, or groups.

[0084] Any of the devices, kits, methods, and/or procedures described herein can include or be performed with a composition CC (see FIG. 1) formulated to detect a target particle by producing (or causing the production of) a colorimetric output PCO (See FIGS. 4, 5B-5D, 7, 8, 9, and 1 1). The composition includes a combination of an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) (see FIG. 6A), an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN) (see FIG. 6B), and an effective amount of iron. As used herein, an “effective amount” is an amount sufficient to produce (or cause the production of) a desired colorimetric output (e.g., a colorimetric output having a desired color and intensity). For example, the composition may be useful for the detection of an actinide (e.g., elements having atomic numbers from 89 to 103, such as uranium, plutonium, and americium). The composition may also be useful for the detection of certain transition metals and/or certain post-transition metals (including deposits thereof), such as bauxite, copper, zinc, nickel, aluminum, cobalt, and/or cadmium. Accordingly, an effective amount of the constituents present in the composition may be an amount of Br-PADAP, an amount of PAN, and an amount of iron that produces a desired or predetermined colorimetric output on a condition that the composition is in contact with the target particle (e.g., the actinide and/or transition metal). Said another way, in some embodiments, the composition includes Br-PADAP, PAN, and iron in effective amounts such that on a condition that the composition is in contact with a target actinide particle a desired or predetermined colorimetric output is produced.

[0085] In some embodiments the Br-PADAP of the composition is a dye. As a dye, the Br-PADAP absorbs a portion of the electromagnetic spectrum, has at least one chromophore, is a conjugated system, and exhibits a resonance of electrons. Accordingly, without being bound by theory, the formulations of the composition described herein produce the enhanced colorimetric output via an interaction between the Br-PADAP and the target particle that affects an energy state of the Br-PADAP and, therefore, an absorbance of a portion of the electromagnetic spectrum. In other words, Br-PADAP in the absence of a target particle has a first energy state that absorbs a first portion of the electromagnetic spectrum and a second energy state that absorbs a second, different portion of the electromagnetic spectrum on a condition that the Br-PADAP is in contact with the target particle. For example, the first energy state of the Br-PADAP can absorb the first portion of the electromagnetic spectrum such that a first color (e.g., as depicted in FIG. 5A) can be observed under a white light. However, on contact with the target particle, the Br-PADAP transitions to the second energy state that absorbs the second, different portion of the electromagnetic spectrum such that a second color (e.g., as depicted in FIGS. 5B-D) can be observed under a white light.

[0086] On a condition that the Br-PADAP is in contact with the target particle (e.g., an actinide such as uranium, plutonium, and/or americium), the Br-PADAP interacts with the target particle but does not react therewith. In other words, without being bound by theory, the Br-PADAP has a primary interaction with the target particle that does not result in ionic or covalent bonding with the target particle to form a molecule. As such, the effect of the presence of the target particle on the energy state of the Br-PADAP is dependent, at least in part, on the molecular distance between the Br-PADAP and the target particle. For example, the molecular distance between Br-PADAP and the target particle can affect the interactions of the charges on the anions and cations.

[0087] In some embodiments, the colorimetric output resulting from the interaction between the Br-PADAP and the target particle is increased by the PAN and iron included within the composition. It has been discovered that the inclusion of both PAN and iron increases the intensity (e.g., the vibrancy) of a colorimetric output relative to the colorimetric output produced by compositions including Br-PADAP alone and compositions including Br-PADAP and PAN. For example, FIG. 9 is a photograph showing the increased colorimetric intensity that results when a Br-PADAP:PAN:iron composition (vial to the right) contacts uranium in solution versus when a Br-PADAP: PAN composition (vial to the left) contacts the same concentration of uranium in solution. Without being bound by theory, it is believed that the inclusion of the iron molecules and the PAN molecules within the composition causes the reduction of the molecular distance between the Br-PADAP and the target particle, thereby increasing the interaction therebetween. Similarly stated, it is believed that the iron and PAN within the composition cause the Br-PADAP to be maintained at a closer molecular distance to the target particle than would occur without the inclusion of iron and PAN within the composition, thereby causing the production of an enhanced colorimetric output. While the inclusion of PAN alone with the Br-PADAP may produce an enhanced colorimetric output when compared to that produced by Br-PADAP alone (i.e., it is believed that PAN can decrease the Br-PADAP-target particle molecular distance by a first amount), an interaction between the PAN and the iron along with Br-PADAP has been shown to produce an enhanced colorimetric output when compared to that produced by Br-PADAP and PAN (see, e.g., FIG. 9). The enhanced colorimetric output (e.g., the increased intensity of the output) is believed to be the result of the PAN and iron causing the Br-PADAP-target particle molecular to be decreased by a distance by a second, greater amount, resulting in an increase in the intensity of the colorimetric output.

[0088] The observed desirable increase in the intensity of the colorimetric output in response to the inclusion of iron in the composition is a surprising result. Specifically, when attempting to detect a target particle, such as an actinide, iron is a known interference to the production of the desired colorimetric output. For example, on a condition that a composition including Br-PADAP alone is in contact with molecules of iron, a colorimetric output that is a shade of purple is produced. The shade of purple produced when in contact with iron is similar to the shade of purple produced by the same composition in contact with uranium. As such, the presence of iron can be said to interfere with the detection of the uranium. Theory would suggest that the inclusion of PAN in addition to the Br-PADAP would increase the intensity of the colorimetric output in response to the contact with iron and, thereby, increase the effect of the interference of the iron. However, it has been discovered that an interaction between the PAN and the iron actually negates the interference of the iron and increases the discernability of the colorimetric output of the Br-PADAP:PAN:iron composition in contact with the target particle.

[0089] FIGS. 9-11 illustrate the observed desirable increase in intensity (e.g., vibrancy) of the colorimetric output resulting from the inclusion of iron in the Br-PADAP AN: iron composition. In FIG. 9, the concentration of the uranium solution in both vials is the same (1X10'⁴M) and the images of both vials were captured at the same time under the same lighting conditions. The lighter purple color of the first vial Vi (i.e., the vial on the left) corresponds to the colorimetric output of a Br-PADAP:PAN composition having an absence of iron. The darker purple color of the second vial V2 (i.e., the file on the right) corresponds to the colorimetric output PCO of the Br-PADAP:PAN:iron composition in contact with uranium. Table 1 provides the formulations used in this example.

Table 1: Test Formulations

[0090] The increase in intensity with the V2 formulation is apparent to an observer, as depicted in FIG. 9, which shows a darker, more vibrant shade of purple, that is easier to visually observe. Further, the change in the colorimetric output resulting from the inclusion of iron (e.g., the increase in intensity) can, for example, be described (e.g., quantified) using values generated via a raster graphics editor (e.g., photo editing software). As depicted by FIGS. 10 and 11 insofar as the images of both vials were captured under the same lighting conditions and the volume of the uranium solution in each vial is substantially the same, color samples taken via the raster graphics editor were analyzed at a specified distance from a support surface. The raster graphics editor was used to characterize the color samples by producing a measurement of both RGB values and CMYK values. The RGB values are often used to characterize colors on a digital display and correspond to the amount of each color displayed within a range of 0-255. An RGB value of 0, 0, 0 (i.e., 0 for each of red, green and blue) is the color black (i.e., the darkest or most visible color). Conversely, an RGB value of 255, 255, 255 (i.e., the maximum color of each of red, green and blue) is the color white (i.e., the lightest or least visible color). Thus, the lower the values on the RGB scale, the darker the color. The CMYK values are often used to characterize colors on a printed display and correspond to the amount of each color displayed as a percentage (0-100%). A CMYK value of 0, 0, 0, 0 (i.e., 0 for each of cyan, magenta, yellow, and black) is the color white (i.e., the lightest possible coloring). Conversely, a CMYK value of 100, 100, 100, 100 is the color black (i.e., the darkest or most visible color). Thus, the higher the values on the CMYK scale, the darker the color. [0091] In FIG. 10, the sample of the lighter purple produced by the Br-PADAP:PAN composition was taken at a first sampling point TP1 and analyzed via the raster graphics editor. As a result, the lighter shade of purple is quantified by RGB values 111,51,43 and by the CMYK values 36,80,77,43. Additional values can also be used to further describe the shade of purple produced by the composition that is devoid of iron, such as a hue of 7 degrees, saturation of 61%, and a balance of 44%. Similarly, in FIG. 11, the sample of the darker purple produced by the Br-PADAP:PAN:iron composition was taken at a second sampling point TP2 and analyzed via the raster graphics editor. The increase in intensity from the first vial Vi to the second vial V2 is reflected by the descriptors of the shade of purple sampled at the second sampling point TP2. Specifically, the darker, more intense shade of purple produced in the presence of iron can be described by RGB values 62,26,28 and by the CMYK values 49,80,69,70. Additional values can also be used to further describe the more intense shade of purple, such as a hue of 357 degrees, a saturation of 50%, and a balance of 24%. It should be appreciated that the precise RGB values and/or CMYK values can vary depending on lighting conditions, container shape, background color, and various other factors. Nevertheless, the changes in the numerical descriptors between the color sampled from the first vial Vi and the color sampled from the second vial V2 are descriptive of the increase in intensity that is observable to the naked eye as a result of the inclusion of iron in the Br-PADAP:PAN:iron composition. Specifically, the colorimetric output produced by the Br-PADAP AN: iron composition was characterized by RGB and/or CMYK values that indicate a darker, more vibrant shade of purple, that is easier to visually observe.

[0092] In some embodiments, the composition (i.e., the Br-PADAP:PAN:iron composition) is a dry powder composition that is formulated to dissolve in contact with a solvent. As such, in some embodiments, the composition is a solution. To produce the predetermined colorimetric output, the effective amount of Br-PADAP in the solution and the effective amount of PAN in the solution have a volumetric ratio that is in the range of 1 :1 to 3: 1. For example, in some embodiments, the ratio of Br-PADAP to PAN can be 2: 1, such that the composition includes twice as many parts of Br-PADAP for every part of PAN. A ratio of the effective amount of iron in the solution and the effective amount of PAN in the solution is in the range of 1 :20 to 1 :50. For example, in some embodiments, the composition can include between about 30 and about 40 times the parts of PAN to parts of iron. [0093] In some embodiments, the Br-PADAP:PAN:iron composition can be a solution with the concentration of each component being defined in terms of molarity. In some embodiments, the effective amount of Br-PADAP in the solution is in a range of 1X10'³M to 1X10'⁵M. For example, the effective amount of Br-PADAP in the solution can be a concentration of 1X10'⁴M. Similarly, the effective amount of PAN in the solution is in a range of 1X10’³M to 1X10'⁶M. For example, the effective amount of PAN in the solution can be a concentration of 1X10'⁴M. Additionally, the effective amount of iron in the solution is in a range of 1X10‘⁵M to 1X10’⁷M. For example, the effective amount of iron can be a concentration in the range of 1X10’⁶M to 5xlO'⁶M (e.g., 3.5X10’⁶M).

[0094] In some embodiments, the iron within the Br-PADAP:PAN:iron composition can be a soluble ferrous iron. In other words, the iron can be in a form that is dissolvable in alcohol to form a solution. For example, the iron can be one of iron(II) nitrate or iron(II) chloride. In some embodiments, the iron of the Br-PADAP:PAN:iron composition can be an insoluble ferrous iron. For example, the iron can be iron(II) oxide and be insoluble in alcohol. However, in some embodiments, the iron(II) oxide can be dissolved into a solution via an acid prior to introduction to a Br-PADAP:PAN solution to form the Br-PADAP:PAN:iron composition.

[0095] In some embodiments, the colorimetric output can, for example, be maintained (e.g., from within a solution or a detection surface) for at least 24 hours. In some embodiments, the colorimetric output can be maintained for between 4 hours and 24 hours. In some embodiments, the colorimetric output can be maintained for between 12 hours and 36 hours. In some embodiments, the colorimetric output can be maintained for between 24 hours and 48 hours. In some embodiments, the colorimetric output can be maintained for as long as one week. This allows the compositions, kits, and methods described herein to be maintained for verification or documentation purposes.

[0096] In some embodiments, the colorimetric output can be produced within 5 minutes after the composition is placed in contact with the target particle. In some embodiments, the colorimetric output can be produced within 1 second to 5 minutes after the composition is placed in contact with the target particle. In some embodiments, the colorimetric output can be produced within 10 seconds to 2 minutes after the composition is placed in contact with the target particle. In some embodiments, the colorimetric output can be produced within 30 seconds to 1 minutes after the composition is placed in contact with the target particle. The rapid production of the colorimetric output allows users to quickly ascertain the presence of the target particle.

[0097] As previously discussed with regards to the surprising effect of the inclusion of iron in the composition, contact with certain molecules can interfere with the production of the predetermined colorimetric output. These molecules can be referred to as known interferences. The known interferences can include elements that are known to bind with Br-PADAP and that may have a detrimental effect on the interaction between the Br-PADAP and the target particle. For example, cadmium, cobalt, copper, iron, manganese, zinc, and nickel are known to bind with Br-PADAP. As such, in some embodiments, the composition can include an effective amount of a masking agent. The masking agent can be formulated or selected to block the interfering effect of at least one interference substance on the production of the predetermined colorimetric output. For example, in some embodiments, the composition can include an effective amount of triethanolamine. Triethanolamine is a tertiary amino compound that, in an effective amount, blocks the effect of at least one of the identified interference substances without affecting the production of the predetermined colorimetric output on a condition that the Br-PADAP:PAN:iron composition is in contact with the target particle.

[0098] Although the compositions are described above as producing (or causing production of) colorimetric outputs that can be visually read and interpreted when viewed in ambient (or white light) conditions, in other embodiments, the compositions and kits described herein can produce colorimetric output that can be read by an instrument that employs spectroscopy techniques. Similarly stated, in some embodiments, a method can include evaluating a colorimetric output produced by (or facilitated by) any of the compositions described herein using a spectroscopy instrument. Such instruments can include a UV-vis spectroscopy instrument, which can expose the colorimetric output to an incident light having a wavelength that is within the ultraviolet or visible range (e.g., between about 100 nanometers and about 900 nanometers) and then evaluating the light absorbance of the colorimetric output. In this manner, a spike portion of the absorbance spectrum can be identified (i.e., a peak wavelength of absorption) and used to identify whether a target particle is present. In this manner, the colorimetric output can be “read” both visually (i.e., via the naked eye) or by an instrument. Additionally, the compositions, kits and methods described herein can be used to detect multiple different target particles (e.g., uranium and plutonium) by producing different colorimetric outputs for the different target particles. The different colorimetric outputs can have different peak wavelengths of absorption when analyzed using a spectroscopy instrument, thus allowing for particles of different type (e.g., uranium, plutonium, americium) to be detected.

[0099] For example, referring to FIG. 7, the colorimetric output PCO is characterized by an identifying absorption spike portion SP in response to exposure to an incident light (e.g., a light source of a spectroscopy instrument, which can have a wavelength between about 100 nanometers and 900 nanometers). In other words, the colorimetric output PCO can, in some embodiments, be represented by a signature descriptive of the absorption spectrum when exposed to incident light. The identifying spike portion SP has a wavelength WL (i.e., a peak absorbance wavelength) that corresponds to the composition on a condition that the composition is in contact with a target particle. The identifying spike portion SP has a maximal magnitude MM at the wavelength WL. The wavelength WL of the identifying spike portion SP can vary depending on the type of target particle that is in contact with the composition. In other words, the wavelength WL of the identifying spike portion SP corresponds to the energy state of the Br-PADAP due to the interaction with the target particle. As such, the wavelength WL of the spike portion SP can be indicative of the presence of a particular molecule (e.g., uranium) in contact with the composition.

[0100] In some embodiments, the composition can be in contact with more than one type of target particle. In such conditions, as depicted in FIG. 8, the colorimetric output PCO can have a first identifying absorption spike portion SPi in response to exposure to an incident light (e.g., a light source of a spectroscopy instrument, which can have a wavelength between about 100 nanometers and 900 nanometers). The first identifying spike portion SPi has a first wavelength WLi (i.e., a first peak absorbance wavelength) that corresponds to a first target particle (i.e., a first elemental target particle). The first spike portion SPi can have a first maximal magnitude MMi at the first wavelength WLi. The colorimetric output PCO can also have a second identifying absorption spike portion SP2. The second identifying spike portion SP2 has a second wavelength WL2 (i.e., a second peak absorbance wavelength) that corresponds to a second target particle (i.e., a second elemental target particle that is different than the first target particle). The second spike portion SP2 can have a second maximal magnitude MM2 at the second wavelength WL2. Accordingly, each target particle in contact with the Br-PADAP:PAN:iron composition can be identified by the respective identifying absorption spike portions.

[0101] By providing an intense colorimetric output, the compositions described herein can allow for detection of low amounts of target particles. For example, in some embodiments, the target particle is uranium. On a condition that the Br-PADAP:PAN:iron composition is in contact with at least 2.4x1 O’⁶ grams of the uranium, the colorimetric output PCO is produced. Similarly, on a condition that the uranium is in a target particle solution, the colorimetric output can be produced at a concentration of 100 parts-per-billion or greater. In other words, any concentration of the uranium in the target particle solution greater than 100 parts-per-billion results in the production of the colorimetric output. As depicted in FIGS. 5B, 9, and 11, on a condition in which the Br-PADAP AN: iron composition is in contact with uranium, the colorimetric output PCO is a shade of purple when viewed under a white light. The shade of purple can be defined and/or described using values generated via a raster graphics editor (e.g., photo editing software). For example, as depicted in FIG. 11, the shade of purple can optionally be defined by the RGB values 62,26,28 and by the CMYK values 49,80,69,70. Additional values can also be used to further define and/or describe the shade of purple, such as a hue of 357 degrees, saturation of 50%, and a balance of 24%.

[0102] In some embodiments, the target particle is plutonium. On a condition that the Br-PADAP:PAN:iron composition is in contact with at least 2.4xl0'⁶ grams of the plutonium, the colorimetric output PCO is produced as depicted in FIG. 5C. Similarly, on a condition that the plutonium is in a target particle solution, the colorimetric output can be produced at a concentration of 100 parts-per-million or greater. In other words, any concentration of the plutonium in the target particle solution greater than 100 parts-per-million results in the production of the colorimetric output. As depicted in FIGS. 5C, on a condition in which the Br-PADAP:PAN:iron composition is in contact with plutonium, the colorimetric output PCO is a shade of peach when viewed under a white light. The shade of peach can be defined and/or described using values generated via a raster graphics editor (e.g., photo editing software).

[0103] In some embodiments, the target particle is americium. On a condition that the Br-PADAP:PAN:iron composition is in contact with at least 2.4x1 O'⁶ grams of the americium, the colorimetric output PCO is produced as depicted in FIG. 5D. Similarly, on a condition that the americium is in a target particle solution, the colorimetric output can be produced at a concentration of 100 parts-per-million or greater. In other words, any concentration of the americium in the target particle solution greater than 100 parts-per-million results in the production of the colorimetric output. As depicted in FIGS. 5D, on a condition in which the Br-PADAP:PAN:iron composition is in contact with americium, the colorimetric output PCO is a shade of orange when viewed under a white light. The shade of orange can be defined and/or described using values generated via a raster graphics editor (e.g., photo editing software).

[0104] In some embodiments, the Br-PADAP:PAN:iron composition CC can be a detection solution of a test kit intended for the detection of the target particle. The test kit can, for example, facilitate a determination of the presence or extent of contamination following a hostile action, an accident, and/or an industrial process via the detection of actinides or other target particles with the Br-PADAP: PAN: iron composition CC. FIGS. 1-4 and 12 depict a kit 1100 for the detection of a target particle and methods for the use thereof. As depicted in FIG. 1, some embodiments, the kit 1100 includes a case 1102 containing at least a container 1110 with a delivery member 1112, a portion of detection solution 1120, and a collection member 1150. In some embodiments, the detection solution 1120 includes effective amounts of 2-(5-Bromo-2-pyridylazo)-5- (di ethyl ami no)phenol (Br-PADAP), l-(2-Pyridylazo)-2-naphthol (PAN), and iron. In other words, in some embodiments, the detection solution 1120 is the Br-PADAP:PAN:iron composition CC. As such, the kit 1100 is configured to determine the presence of a target particle via a colorimetric change on a condition that the detection solution 1120 is in contact with the target particle (e.g., a target actinide particle). In some embodiments, the target particle can be uranium, plutonium, americium, and/or a transition metal.

[0105] As depicted in FIGS. 1-4, the collection member 1150 of the kit 1100 has a detection surface 1152 for contacting an object OBJ (see FIG. 2). The object OBJ to be sampled can be, for example, a structure, a man-made surface, a natural surface, a vehicle, and/or a living being. The detection surface 1152 can include coloring and/or other features that enhance the detectability of the colorimetric output PCO. For example, the detection surface 1152 can be formed with a light colored (e.g., a shade of white) background such that the colorimetric output PCO is more visible than would be the case if the detection surface 1152 were darker. In some embodiments, the collection member 1150 and/or detection surface 1152 can include a series of colorimetric indicators having a range of colors associated with a range of colors that may be produced by the colorimetric output PCO to assist the user in determining the results of the test (see also the colorimetric indicators 1182 described herein). For example, in some embodiments, the edge of the collection member 1150 can include a color strip having the shade of purple that corresponds to the colorimetric output PCO produced indicating the presence of uranium. In some embodiments, the edge of the collection member 1150 can include a color strip having the shade of peach that corresponds to the colorimetric output PCO produced indicating the presence of plutonium. In some embodiments, the edge of the collection member 1150 can include a color strip having the shade of orange that corresponds to the colorimetric output PCO produced indicating the presence of americium. In this manner, the collection member 1150 can contribute to reducing the amount of user judgment required to accurately read the test.

[0106] The delivery member 1112 is configured to convey a portion of the detection solution 1120 onto the detection surface 1152. On a condition that the detection solution 1120 is in contact with the target particle, a colorimetric output PCO is produced on the detection surface 1152. In some embodiments, the colorimetric output PCO is maintained (e.g., is visible and/or detectable on the detection surface 1152) for at least 24 hours.

[0107] In some embodiments, contacting the object OBJ with the collection member 1150 includes contacting the object OBJ via a dynamic motion. The dynamic motion can include moving at least a portion of the detection surface 1152 between a first position and a second position. For example, as depicted in FIG. 2, the collection member 1150 can be brought into contact with a surface of the object (e.g., a vertical surface, a horizontal surface, and/or a surface at any other angle). Upon contact with the surface, the collection member 1150 is, in some embodiments, moved dynamically relative to the surface of the object. As depicted in FIG. 3, the dynamic movement can include moving the collection member 1150, and thus the detection surface 1152, along a path Pi (e.g., a raster path) across the surface of the object OBJ. The path Pi can be arranged so that the movement of the collection member 1150 trends in a generally upward direction as depicted in FIG. 3. This arrangement facilitates the collection of any target particles present on the surface of the object OBJ rather than the particles being displaced (e.g., falling free from the surface) in response to the pull of gravity. In some embodiments, moving the portion of the detection surface 1152 between the first position and the second position can include a rotational motion of the collection member 1150 relative to the surface of the object OBJ. The rotational motion can be used alone or in combination with a linear or curvilinear motion of the collection member 1150.

[0108] The detection surface 1152 is configured to retain the target particle following contact with the object OBJ. As such, in some embodiments, the collection member 1150 can be an electrostatic cloth. The electrostatic cloth can have a negative charge that attracts and/or retains the target particle. In some embodiments, the collection member 1150 can be a swab that is premoistened with deionized water or with a portion of the detection solution 1120. Prior to use, the premoistened swab can be stored in a hermetically sealed package 1104 (see FIG. 1). The collection member 1150 can be removed from the hermetically sealed package 1104 to contact the object OBJ. In some embodiments, however, the collection member 1150 can be a dry swab configured to be moistened contemporaneously with the use of the kit 1100 to detect the target particle. As such, the kit 1100 in some embodiments, includes a portion of deionized water W. The portion of the deionized water W is applied to the dry swab to moisten the dry swab prior to contact with the object OBJ. In some embodiments, the dry swab is configured to receive a portion of the detection solution 1120 prior to contact with the object OBJ. The moist nature of the swab, whether premoistened or moistened contemporaneously with the testing, facilitates the retention of the target particle by the detection surface 1152 following contact with the object OBJ.

[0109] As depicted in FIG. 1, in some embodiments, the container 1110 includes a delivery member 1112. The delivery member 1112 can, for example, be a dosing portion, an atomization mechanism, a dropper, a pipette, a porous applicator, or other mechanism for dispensing a portion of the detection solution 1120 contained within the container 1110.

[0110] In some embodiments, the delivery member 1112 can be a spray apparatus configured to atomize a portion of the detection solution 1120 for delivery. The atomized portion of the detection solution 1120 (e.g., an atomized portion of the Br-PADAP:PAN:iron composition CC) can be conveyed onto the detection surface 1152 of the collection member 1150. In some embodiments, the detection surface 1152 can be moistened via the atomized portion of the detection solution 1120 prior to contact with the surface of the object OBJ. The detection solution 1120 can then be brought into contact with the target particle via the contact between the collection member 1150 and the surface to be tested. On a condition that the target particle is retained by the detection surface 1152, the predetermined colorimetric output PCO can be observed following the separation of the collection member 1150 from the surface. As depicted in FIG. 4, however, in some embodiments the atomized portion of the detection solution 1120 can be conveyed to the detection surface 1152 following contact between the detection surface 1152 and the surface. This conveyance of the detection solution 1120 results in the production of the predetermined colorimetric output PCO on a condition that the target particle is present on the detection surface 1152 following the contact with the surface.

[OUl] In some embodiments, the detection solution 1120 can be conveyed directly onto the object to be tested. For example, an atomized portion of the detection solution 1120 can be conveyed onto the object via the delivery member 1112 configured as a spray apparatus. In such embodiments, the portion of the detection solution is conveyed onto the detection surface via the contacting of the object OBJ with the detection surface 1152. The predetermined colorimetric output PCO can then be detected (e.g., observed) on the detection surface 1152 following contact between the collection member 1150 and the surface of the object OBJ.

[0112] In some embodiments, conveying the detection solution 1120 directly onto the object to be tested can result in at least traces of the predetermined colorimetric output PCO being observable on the surface of the object OBJ even after contact with the collection member 1150. The detectability of the traces of the predetermined colorimetric output PCO can vary depending on the color of the surface to which the detection solution 1120 is applied. The presence of the traces of the predetermined colorimetric output PCO is indicative that the target particle was present on the object OBJ at the time of testing. In other words, the traces of the predetermined colorimetric output PCO can indicate that the object was contaminated with an actinide at time of testing. Accordingly, the presence of the traces of the predetermined colorimetric output PCO on various objects can inform response decisions, such as the establishment of a contamination according. Similarly, conveying the detection solution 1120 directly onto the object to be tested can leave behind at least traces of a shade of yellow corresponding to the visible color of the Br-PADAP: PAN: iron composition CC in the absence of the target particle. Accordingly, such negative traces indicate that the object was free from contamination in the tested region at the time of testing (e.g., a negative result). As such, the presence of the negative traces can inform response decisions.

[0113] In some embodiments, the delivery member 1112 is a dosing portion. The dosing portion is configured to dispense a specified portion of the detection solution 1120. The dosing portion is formed such that an amount of the detection solution 1120 in excess of the specified portion is returned to the container 1110. As such, the detection solution 1120 can, for example, be applied to the detection surface 1152 of the collection member 1150 by depositing the portion of the detection solution 1120 from the dosing portion of the container 1110 (e.g., a solution container). The portion of the detection solution 1120 deposit from the dosing portion of the container 1110 can be accomplished following the contacting of the object with the collection member 1150. The use of a dosing portion can ensure that a sufficient but not excessive or wasteful portion of the detection solution 1120 is applied to the collection member 1150 thereby enhancing the accuracy of the test results while preserving a maximum number of available testing iterations per kit 1100.

[0114] To produce the predetermined colorimetric output, the effective amount of Br-PADAP in the solution and the effective amount of PAN in the detection solution 1120 have a ratio that is in the range of 1 : 1 to 3 : 1 in some embodiments. For example, in some embodiments, the ratio of Br-PADAP to PAN can be 2: 1, such that the detection solution 1120 includes twice as many parts of Br-PADAP for every part of PAN. A ratio of the effective amount of iron in the detection solution 1120 and the effective amount of PAN in the detection solution 1120 is in the range of 1 :20 to 1 :50. For example, in some embodiments, the detection solution 1120 can include between about 30 and about 40 times the parts of PAN to parts of iron.

[0115] In some embodiments, the detection solution 1120 (e.g., the Br-PADAP:PAN:iron composition) can be a solution with the concentration of each component being defined in terms of molarity. In some embodiments, the effective amount of Br-PADAP in the detection solution 1120 is in a range of 1X10’³M to 1X10‘⁵M. For example, the effective amount of Br-PADAP in the detection solution 1120 can be a concentration of 1X10'⁴M. Similarly, the effective amount of PAN in the detection solution 1120 is in a range of 1X10'³M to 1X10'⁶M. For example, the effective amount of PAN in the detection solution 1120 can be a concentration of lxlO'⁴M. Additionally, the effective amount of iron in the detection solution 1120 is in a range of 1X10'⁵M to 1X10'⁷M. For example, the effective amount of iron can be a concentration in the range of 1X10’⁶M to 5X10'⁶M (e.g., 3.5X10’⁶M).

[0116] In some embodiments, the iron of the detection solution 1120 can be a soluble ferrous iron. In other words, the iron can be in a form that is dissolvable in alcohol to form a solution. For example, the iron can be one of iron(II) nitrate or iron(II) chloride. In some embodiments, the iron of the detection solution 1120 can be an insoluble ferrous iron. For example, the iron can be iron(II) oxide and be insoluble in alcohol. However, in some embodiments, the iron(II) oxide can be dissolved into a solution via an acid prior to introduction to a Br-PADAP:PAN solution to form the Br-PADAP:PAN:iron composition.

[0117] In some embodiments, the detection solution 1120 can include an effective amount of a masking agent. The masking agent can be configured to block the effect of at least one interference substance on the production of the predetermined colorimetric output PCO. For example, the detection solution 1120 can include an effective amount of triethanolamine. Triethanolamine is a tertiary amino compound that, in an effective amount, blocks the effect of at least one of the identified interference substances without affecting the production of the predetermined colorimetric output PCO on a condition that the detection solution 1120 is in contact with the target particle.

[0118] In some embodiments, the target particle is uranium. On a condition that the detection solution 1120 is in contact with at least 2.4xl0^-6 grams of the uranium, the colorimetric output PCO is produced. Said another way, in some embodiments, the colorimetric output PCO is produced on a condition that uranium is present on the detection surface 1152 at a concentration of at least 0.022 g/m². The colorimetric output PCO is a shade of purple under a white light. In other words, the observation of the specified shade of purple on the detection surface 1152 or on the surface of the object OBJ is indicative of the presence of at least 2.4xl0'⁶ grams of the uranium.

[0119] In some embodiments, the target particle is plutonium. On a condition that the detection solution 1120 is in contact with at least 2.4xl0'⁶ grams of the plutonium, the colorimetric output PCO is produced. Said another way, in some embodiments, the colorimetric output PCO is produced on a condition that plutonium is present on the detection surface 1152 at a concentration of at least 0.023 g/m². The colorimetric output PCO is a shade of peach under a white light. In other words, the observation of the specified shade of peach on the detection surface 1152 or on the surface of the object OBJ is indicative of the presence of at least 2.4x1 O'⁶ grams of the plutonium.

[0120] In some embodiments, the target particle is americium. On a condition that the detection solution 1120 is in contact with at least 2.4x10‘⁶ grams of the americium, the colorimetric output PCO is produced. Said another way, in some embodiments, the colorimetric output PCO is produced on a condition that americium is present on the detection surface 1152 at a concentration of at least 0.023 g/m². The colorimetric output PCO is a shade of orange under a white light. In other words, the observation of the specified shade of orange on the detection surface 1152 or on the surface of the object OBJ is indicative of the presence of at least 2.4xl0’⁶ grams of the americium.

[0121] In some embodiments, the detection surface 1152 of the collection member 1150 is configured to be read by an instrument following the application of the detection solution 1120. In such embodiments, the target parti cle(s) on the detection surface 1152 can then be identified based at least in part on the absorbance spectrum that characterizes the colorimetric output PCO. The absorbance spectrum can be produced by any suitable instrument, such as a UV-vis spectroscopy instrument, which can expose the colorimetric output PCO to an incident light having a wavelength that is within the ultraviolet or visible range (e.g., between about 100 nanometers and about 900 nanometers) and then evaluating the light absorbance of the colorimetric output. As depicted in FIG. 7, the predetermined colorimetric output PCO is characterized by an identifying spike portion SP in response to exposure to an incident light (e.g., a light source of a spectroscopy instrument, which can have a wavelength between about 100 nanometers and 900 nanometers). In other words, the predetermined colorimetric output PCO can, in some embodiments, be represented by a signature descriptive of the absorption spectrum of the detection solution 1120 when exposed to incident light. The identifying spike portion SP has a wavelength WL (i.e., a peak absorbance wavelength) that corresponds to the detection solution 1120 on a condition that the detection solution 1120 is in contact with a target particle (e.g., a target actinide and/or transition metal). The identifying spike portion SP has a maximal magnitude MM at the wavelength WL. The wavelength WL of the identifying spike portion SP can vary depending on the type of target particle that is in contact with the composition. In other words, the wavelength WL of the identifying spike portion SP corresponds to the energy state of the Br-PADAP due to the interaction with the target particle. As such, the wavelength WL of the spike portion SP can be indicative of the presence of a particular molecule in contact with the detection solution 1120.

[0122] In some embodiments, the composition can be in contact with more than one type of target particle (e.g., uranium and plutonium). In such conditions, as depicted in FIG. 8, the predetermined colorimetric output PCO can have a first identifying absorption spike portion SPi in response to exposure to an incident light (e.g., a light source of a spectroscopy instrument, which can have a wavelength between about 100 nanometers and 900 nanometers). The first identifying spike portion SPi has a first wavelength WLi (i.e., a first peak absorbance wavelength) that corresponds to a first target particle (i.e., a first elemental target particle, such as uranium). The first spike portion SPi can have a first maximal magnitude MMi at the first wavelength WLi. The predetermined colorimetric output PCO can also have a second identifying absorption spike portion SP2 that is different from the first identifying spike portion SPi. The second identifying spike portion SP2 has a second wavelength WL2 (i.e., a second peak absorbance wavelength) that corresponds to a second target particle (i.e., a second elemental target particle, such as plutonium, that is different than the first target particle). The second spike portion SP2 can have a second maximal magnitude MM2 at the second wavelength WL2. Accordingly, the first target particle can be determined based at least in part on the first identifying absorption spike portion SPi and the second target particle can be determined based at least in part on the second identifying absorption spike portion SP2.

[0123] As depicted in FIG. 1, in some embodiments the kit 1100 includes a preservation container 1170. The preservation container 1170 is configured to receive the collection member 1150 following contact with the object OBJ (FIG. 2) the preservation container 1170 includes an observation portion 1172. The observation portion 1172 can be a transparent portion of the preservation container 1170 that is positioned to facilitate viewing of the predetermined colorimetric output PCO on the detection surface 1152 on a condition that the collection member 1150 is positioned within the preservation container 1170. In some embodiments, the preservation container 1170 can include an opaque or colored portion surrounding the observation portion 1172 to “frame” or accentuate viewing the colorimetric output PCO via observation portion. In some embodiments, the preservation container 1170 includes include a series of colorimetric indicators having a range of colors associated with a range of colors that may be produced by the colorimetric output PCO to assist the user in determining the results of the test of the types described herein for the collection member 1150 or instruction sheet 1180. The preservation container 1170 can include a destructible seal (not shown) configured to hermetically seal the collection member 1150 within the preservation container 1170 and to provide a tamper indication upon disruption.

[0124] Referring still to FIG. 1, in some embodiments the kit 1100 includes an instruction sheet 1180 (e.g., an instruction card). The instruction sheet 1180 can include printed instructions directing the proper usage of the collection member 1150 and the detection solution 1122 detect the target particle. The instruction sheet 1180 can also include a set of colorimetric indicators 1182. The colorimetric indicators 1182 correspond to positive and negative colorimetric results under white light, such as depicted in FIGS. 5A-5D. In other words, by comparing the set of colorimetric indicators 1182 to the predetermined colorimetric output PCO as described herein, an operator of the test kit can detect the target particle.

[0125] In some embodiments, the kit 1100 can facilitate implementation of the method 60 to detect a target particle as described by the flow chart of FIG. 12. In other words, the method 60 can employ the Br-PADAP:PAN:iron composition to produce a colorimetric output in the presence of the target particle as described herein. It should be appreciated that the method 60 can be implemented via any of the structures and/or procedures described herein.

[0126] At 62, the method 60 includes contacting an obj ect with a collection member to transfer the target particle from the object to a detection surface of the collection member. At 64, the method 60 includes applying a detection solution to a detection surface of the collection member, the detection solution comprising an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN), and an effective amount of iron. On a condition that the detection solution is in contact with the target particle, a colorimetric output is produced on the detection surface, at 66. [0127] Although various embodiments have been described as having particular features and/or combinations of components, other embodiments are possible having a combination of any features and/or components from any of embodiments as discussed above.

Claims

What is claimed is:

1. A composition for detection of a target particle, comprising: an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP); an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN); and an effective amount of iron, wherein on a condition that the composition is in contact with the target particle, a colorimetric output is produced.

2. The composition of claim 1, wherein: the target particle is an actinide.

3. The composition of claim 1, wherein: the composition is a solution; a ratio of the effective amount of Br-PADAP in the solution and the effective amount of

PAN in the solution is between 1 : 1 and 3: 1; and a ratio of the effective amount of iron in the solution and the effective amount of PAN in the solution is between 1 :20 and 1 :50.

4. The composition of claim 1, wherein: the composition is a solution; the effective amount of Br-PADAP in the solution is in a range of 1X10'³M and 1X10'⁵M; the effective amount of PAN in the solution is in a range of lxlO’³M and 1X10'⁶M; and the effective amount of iron in the solution is in a range of IxlO'^M and lxlO'⁷M.

5. The composition of claim 1, wherein: the composition is a solution; and the iron is a soluble ferrous iron.

6. The composition of claim 5, wherein: the soluble ferrous iron is one of iron (II) nitrate or iron (II) chloride.

7. The composition of claim 1, wherein: the composition is a solution; and the iron is insoluble ferrous iron.

8. The composition of any of claims 1-7, wherein: the target particle is one of uranium, plutonium, or americium.

9. The composition of any of claims 1-7, wherein: the target particle is uranium; the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers; and a wavelength of the identifying absorbance spike portion corresponds to a wavelength associated with the uranium in contact with the composition.

10. The composition of claim 9, wherein: the colorimetric output is a visible shade of purple under a white light.

11. The composition of claim 9, wherein: on condition that the uranium is in a target particle solution, the colorimetric output is produced at a concentration of the uranium in the target particle solution of 100 parts-per-billion or greater.

12. The composition of claim 9, wherein: the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xlO'⁶ grams of the uranium.

13. The composition of any of claims 1-7, wherein: the target particle is plutonium; the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers; and a wavelength of the identifying absorbance spike portion corresponds to a wavelength associated with the plutonium in contact with the composition.

14. The composition of claim 13, wherein: the colorimetric output is a visible shade of peach under a white light.

15. The composition of claim 13, wherein: on condition that the plutonium is in a target particle solution, the colorimetric output is produced at a concentration of the plutonium in the target particle solution of 1 part-per-million or greater.

16. The composition of claim 13, wherein: the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xlO'⁶ grams of the plutonium.

17. The composition of any of claims 1-7, wherein: the target particle is americium; the colorimetric output is characterized by an identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers; and a wavelength of the identifying absorbance spike portion corresponds to a wavelength associated with the americium in contact with the composition.

18. The composition of claim 17, wherein: the colorimetric output is a visible shade of orange under a white light.

19. The composition of claim 17, wherein: on condition that the americium is in a target particle solution, the colorimetric output is produced at a concentration of the americium in the target particle solution of 1 part-per-million or greater.

20. The composition of claim 17, wherein: the colorimetric output is produced on a condition that the composition is in contact with at least 2.4 xl0‘⁶ grams of the americium.

21. The composition of claim 1, wherein: the composition is for detection of a plurality of target particles, the target particle being a first target particle of the plurality of target particles; the colorimetric output is characterized by a first identifying absorbance spike portion in response to exposure to an incident light having a wavelength between about 100 nanometers and about 900 nanometers, the first identifying absorbance spike portion having a wavelength that is associated with the first target particle; and the colorimetric output is characterized by a second identifying absorbance spike portion in response to exposure to the incident light, the second identifying absorbance spike portion having a wavelength that is associated with a second target particle of the plurality of target particles.

22. The composition of any of claims 1-7, wherein: the colorimetric output is maintained for at least 24 hours.

23. The composition of claim 1, wherein: the composition is a dry powder composition that is formulated to dissolve in an aqueous solvent.

24. The composition of any of claims 1-7, further comprising: an effective amount of a masking agent, the masking agent being configured to block an effect of at least one interference substance on the production of the colorimetric output.

25. A composition for detection of a target actinide particle, comprising: 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), l-(2-Pyridylazo)-2-naphthol (PAN), and iron in effective amounts such that on a condition that the composition is in contact with the target actinide particle, a colorimetric output is produced.

26. A kit for detection of a presence of a target particle on an object, comprising: a container having a delivery member; a detection solution within the container, the detection solution comprising effective amounts of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), l-(2-Pyridylazo)-2-naphthol (PAN), and iron; and a collection member having a detection surface for contacting the object, wherein: the detection surface is configured to retain the target particle following contact with the object, the delivery member is configured to convey a portion of the detection solution onto the detection surface, and on a condition that the detection solution is in contact with the target particle, a colorimetric output is produced on the detection surface.

27. The kit of claim 26, wherein: a ratio of the effective amount of Br-PADAP in the detection solution and the effective amount of PAN in the detection solution is between 1 : 1 and 3: 1; and a ratio of the effective amount of iron in the detection solution and the effective amount of PAN in the detection solution is between 1 :20 and 1 :50.

28. The kit of claim 26, wherein: the effective amount of Br-PADAP in the detection solution is in a range of 1X10’³M and 1X10'⁵M; the effective amount of PAN in the detection solution is in a range of 1X10'³M and 1X10’⁶M; and the effective amount of iron in the detection solution is in a range of 1X10'⁵M and 1X10’⁷M.

29. The kit of claim 26, wherein: the iron is a soluble ferrous iron.

30. The kit of any of claims 26-29, wherein: the target particle is one of uranium, plutonium, or americium.

31. The kit of any of claims 26-29, wherein: the target particle is uranium; and the colorimetric output is a visible shade of purple on the detection surface.

32. The kit of claim 31, wherein: the uranium is present on the detection surface at a concentration of at least 0.022 g/m2.

33. The kit of any of claims 26-29, wherein: the target particle is plutonium; and the colorimetric output is a visible shade of peach on the detection surface.

34. The kit of claim 33, wherein: the plutonium is present on the detection surface at a concentration of at least 0.023 g/m2.

35. The kit of any of claims 26-29, wherein: the target particle is americium; and the colorimetric output is a visible shade of orange on the detection surface.

36. The kit of claim 35, wherein: the americium is present on the detection surface at a concentration of at least 0.023 g/m2.

37. The kit of any of claims 26-29, wherein: the colorimetric output is maintained for at least 24 hours.

38. The kit of any of claims 26-29, wherein: the detection solution includes an effective amount of a masking agent, the masking agent being configured to block an effect of at least one interference substance on the production of the colorimetric output.

39. The kit of any of claims 26-29, wherein: the collection member is an electrostatic cloth having a negative charge.

40. The kit of any of claims 26-29, wherein: the collection member is a swab premoistened with deionized water.

41 . The kit of any of claims 26-29, wherein the container is first container, the kit further comprising: a second container containing deionized water; and the collection member is a dry swab configured to receive a portion of the deionized water prior to contact with the object.

42. The kit of any of claims 26-29, wherein: the collection member is a swab premoistened with a portion of the detection solution.

43. The kit of any of claims 26-29, wherein: the collection member is a dry swab configured to receive a portion of the detection solution prior to contact with the object.

44. The kit of any of claims 26-29, wherein: the delivery member is a spray apparatus configured to atomize a portion of the detection solution for conveyance onto the detection surface.

45. The kit of any of claims 26-29, wherein: the delivery member is a spray apparatus configured to atomize a portion of the detection solution for conveyance onto the object; and the portion of the detection solution is conveyed onto the detection surface via the contacting of the object with the detection surface.

46. The kit of any of claims 26-29, wherein: the delivery member is a dosing portion; the dosing portion is configured to dispense a specified portion of the detection solution; and the dosing portion is formed such that an amount of the detection solution in excess of the specified portion is returned to the container.

47. The kit of any of claims 26-29, further comprising: a preservation container configured to receive the collection member following contact with the object, the preservation container including an observation portion positioned to facilitate observation of the colorimetric output on the detection surface.

48. A method for detecting a target particle, comprising: contacting an object with a collection member to transfer the target particle from the object to a detection surface of the collection member; and applying a detection solution to a detection surface of the collection member, the detection solution comprising an effective amount of 2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP), an effective amount of l-(2-Pyridylazo)-2-naphthol (PAN), and an effective amount of iron, wherein on a condition that the detection solution is in contact with the target particle, a colorimetric output is produced on the detection surface.

49. The method of claim 48, wherein: contacting the object with the collection member includes contacting the object via moving at least a portion of detection surface relative to the object between a first position and a second position.

50. The method of claim 48, wherein: a ratio of the effective amount of Br-PADAP in the detection solution and the effective amount of PAN in the detection solution is between 1 : 1 and 3: 1; and a ratio of the effective amount of iron in the detection solution and the effective amount of PAN in the detection solution is between 1 :20 and 1 :50.

51. The method of claim 48, wherein: the effective amount of Br-PADAP in the detection solution is in a range of 1X10'³M and 1X10'⁵M; the effective amount of PAN in the detection solution is in a range of 1X10'⁴M and

1X10’⁶M; and the effective amount of iron in the detection solution is in a range of lxl O^-1M and 1X10'³M.

52. The method of claim 48, wherein: the iron is a soluble ferrous iron.

53. The method of any of claims 48-52, further comprising: detecting a visible shade of purple on the detection surface on a condition that the target particle is uranium; detecting a visible shade of peach on the detection surface on a condition that the target particle is plutonium; and detecting a visible shade of orange on the detection surface on a condition that the target particle is americium.

54. The method of any of claims 48-52, further comprising: exposing the detection surface to an incident light having a wavelength between about 100 nanometers and about 900 nanometers following the applying of the detection solution; and identifying the target particle based at least in part an identifying absorbance spike portion in response to the incident light, the identifying absorbance spike portion has a wavelength that is associated with one of uranium, plutonium, or americium.

55. The method of claim 54, wherein the target particle is a first target particle and the identifying absorbance spike portion is a first identifying absorbance spike portion, the method further comprising: determining the first target particle based at least in part on the first identifying absorbance spike portion; and determining a second target particle based at least in part on a second identifying absorbance spike portion, the second identifying absorbance spike portion being different from the first identifying absorbance spike portion.

56. The method of any of claims 48-52, wherein: the colorimetric output is maintained for at least 24 hours.

57. The method of any of claims 48-52, wherein: the collection member is an electrostatic cloth having a negative charge.

58. The method of any of claims 48-52, further comprising: removing the collection member from a hermetically sealed package, the collection member being a swab premoistened with deionized water.

59. The method of any of claims 48-52, further comprising: applying a portion of deionized water to a dry swab prior to contact with the object.

60. The method of any of claims 48-52, further comprising: removing the collection member from a hermetically sealed package, the collection member being a swab premoistened with a portion of the detection solution.

61. The method of any of claims 48-52, wherein: applying the detection solution to the detection surface of the collection member includes depositing a portion of the detection solution on the detection surface via a spray apparatus following the contacting of the object with the collection member.

62. The method of any of claims 48-52, further comprising: applying the detection solution to the detection surface of the collection member includes depositing a portion of the detection solution on the detection surface via a dosing portion of a solution container following the contacting of the object with the collection member, the dosing portion being configured to dispense a specified portion of the detection solution, the dosing portion being formed such that an amount of the detection solution in excess of the specified portion is returned to the solution container.

63. The method of any of claims 48-52, further comprising: placing the collection member within a preservation container following contact with the object; and observing the colorimetric output on the detection surface via an observation portion of the preservation container.