THC breathalyzer using colorimetric detection system

Abstract

A portable breathalyzer is described that can detect recent THC use. The device is based in a colorimetric reaction for the semi-quantitative detection of THC in exhaled air. The device comprises a cartridge that holds a dye that gives a specific color when it reacts with THC. The intensity of the color formed is directly proportional to the concentration of THC, and a detection system is able to quantify the amount of THC in the breath. Test results are provided immediately and can therefore be applied in road traffic.

Description

[0001] THC BREATHALYZER USING COLORIMETRIC DETECTION SYSTEM

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent App. No. 63 / 564,639, filed March 13, 2024, the complete contents of which are herein incorporated by reference.

[0004] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0005] This invention was made with government support under grant number 15PNIJ-22-GG- 04437-RESS awarded by the National Institute of Justice (NIJ). The government has certain rights in the invention.

[0006] FIELD OF THE INVENTION

[0007] This disclosure generally relates to devices to test for marijuana use and / or measure impairment, and, more specifically, breathalyzer devices capable of THC detection in situ using colorimetric techniques.

[0008] BACKGROUND

[0009] According to the 2021 World Drug Report cannabis is one of the most widely used drugs worldwide. UNODC estimates that almost 4% of the global population aged 15-64 years used cannabis at least once in 2019, the equivalent of some 200 million people. Currently, in the United States, 31 states and the District of Columbia have legalized non-medical cannabis. In 2020, the legal marijuana market in the United States recorded total sales of $18.3 billion. The high profit in part can be attributed to the 2018 Farm Bill, which defines hemp as a cannabis plant or finished product containing 0.3% or less decarboxylated A9-THC and removed hemp from the controlled substances list. As more and more products containing A9-THC are becoming available, concerns about the public health consequences of cannabis use have increased.

[0010] THC can cause impairment and decrease a driver’s capacity and response, making driving under the influence of THC a matter of public health concern. After the legalization of cannabis, several states reported an increase in the number of car accidents, with drivers 25% more likely to crash when under the influence of marijuana.

[0011] Current THC detection devices in the market are collection devices where the exhaled air is collected and captured in a medium that must be sent to a laboratory to be extracted and analyzed using instrumental techniques such as chromatographic techniques.

[0012] SUMMARY

[0013] Some exemplary embodiments provide a portable breathalyzer and cartridge that is able to detect recent THC use. An exemplary device is based on a colorimetric reaction for the semi- quantitative detection of THC in exhaled air. The device comprises a cartridge that holds a dye that gives a specific color when reacting with THC. The intensity of the color formed is directly proportional to the concentration of THC, providing capability to quantify the amount of THC in the breath.

[0014] Embodiments of this disclosure include a chemical foundation for a colorimetric-based THC breathalyzer for the detection of one or more target analytes, in particular, THC and its derivatives. Some exemplary embodiments may be characterized as including a portable color assay. One exemplary application is the detection of driving under the influence of THC. Exemplary devices may be used to monitor drivers on the road in Driving under the Influence (DUID) monitoring. Exemplary devices may be used on-site analysis, giving law enforcement personnel a substantially immediate response, e.g., when testing a driver suspected to be operating a vehicle impaired from marijuana use.

[0015] According to an aspect of some exemplary embodiments, an exemplary device includes a sorptive matrix able to hold inside its structure a dye used for chemical tests for the detection of THC and its derivatives. This sorptive matrix with included dye exhibits a colorimetric reaction with THC. Specific dyes generate specific colors particular to THC (versus CBD, for example). A colorimetric test in exemplary embodiments is very specific to a certain chemical group. An example colorimetric system is the Fast Blue dyes, dyes very specific for cannabinoids. This particular family of exemplary dyes react with THC particles to turn various intensities of red, the intensity being dependent on the amount of THC particles. By contrast the Fast Blue dyes react with CBD particles by turning shades of orange, not red. Accordingly exemplary devices do not risk results which conflate CBD particle presence with THC particular presence. Within the Fast Blue dye family, an exemplary dye is Fast Blue BB (FBBB). Besides shifting to red hues for THC but not for CBD, Fast Blue BB reacted with THC also fluoresces. However, FBBB reacted with THC does not fluoresce. Accordingly, exemplary embodiments may include as an additional or alternative test to checking the visible light spectrum color of the dye whether or not, and at what intensity, a cartridge containing a reagent such as FBBB fluoresces.

[0016] An exemplary sorptive matrix may be adsorptive and / or absorptive. Depending on the embodiment and material of the sorptive matrix, the sorptive matrix may permit some air particles to pass the surface of the sorptive matrix. The sorptive matrix retains the solid microparticles carried by the air. The particles are retained on the surface of the sorptive matrix and / or partially within the sorptive matrix to react with the dye present in the sorptive matrix. The material choice of the sorptive matrix has consequence for the stability of the dye contained in the sorptive matrix.

[0017] An exemplary sorptive matrix may include one or more gels. According to some embodiments, a sorptive matrix may be a ballistic gelatin (BG). According to some embodiments, a sorptive matrix may be a chitosan-based gel. In general, an exemplary gel is preferably nutrient poor to extend the shelf life of the cartridge. Nutrient rich gels such as but not limited to agar have comparatively short shelf life because of susceptibility to mold growth. In some alternative embodiments, a sorptive matrix may be or include one or more resins. Exemplary resins include photocurable / photocured polymeric resins.

[0018] In some embodiments, an exemplary breathalyzer may be multiuse, accepting multiple single use cartridges. In other embodiments, an exemplary breathalyzer may be single use (and disposable after the single use).

[0019] Different from alcohol breathalyzers that work based in a reduction-oxidation reaction (REDOX), exemplary devices herein use a colorimetric reaction. This difference is consequential since the REDOX reactions are not adequately specific, and any compound that could be present in the breath that has the potential to reduce or oxidize the breathalyzer detection system would give a positive result. By contrast, exemplary embodiments herein use one or more reactants (c.g., dyes) which have a reaction specific to THC which is distinguished from any possible reactions with other particles such as CBD.

[0020] Some exemplary devices comprise a spectral system to distinguish different wavelengths of the dye in a cartridge, thereby providing the capacity to evaluate the concentration and the identification of which compound(s) have reacted with the dye after the cartridge has been used with a subject. In some embodiments, photometric results distinguish THC detection from detection of other cannabinoids based on detected wavelengths (corresponding with different color profiles for the different cannabinoids). This is of particular utility in the United States due to the peculiar legal situation of these different compounds in the United States.

[0021] According to some embodiments, a specific 3D resin is mixed with one or more dyes and printed in one or more different shapes to form cartridges. In addition or in the alternative, some exemplary cartridges have at least one support layer made of polymeric resin but which does not contain dyes for THC detection. Rather, a different layer is joined with the supporting polymeric resin layer, and the different layer comprises the at least one dye for THC detection. The different layer may be made of a gel, for example, instead of a polymeric resin.

[0022] A 3D printing technique may be used to produce one or more layers of some exemplary cartridges. The 3D printing process is based on additive manufacturing and can be defined as the process of joining materials to make parts from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing and formative manufacturing methodologies. Various technologies for 3D printing include fused filament fabrication (FFF), stereolithography (SLA), selective laser melting (SLS), inkjet and Polyjet printing, and laminated object manufacturing (LOM).

[0023] SLA has advantages of ease, versatility, and low cost. A main principle of this technique is that photo-curable resins are exposed to a laser and undergo a chemical reaction to become solid. The chemical reaction, called photo-polymerization, may involve multiple chemical compounds such as photo-initiators, additives, and reactive monomer s / oligomers. Usually, these materials are sold in a commercial product known as 3D printing resin.

[0024] An exemplary SLS 3D printing process is as follows. A polymerizable resin mixed with the THC sensitive dye is located in a resin tank. The laser is located above and with the help of a x-y scanning mirror, a laser Beam is formed and directed to the resin tank, where the material will be printed, layer by layer. The printed material builds, upside-down, on the build platform. A wash step may be included to remove the non-polymcrizablc resin attached to the material. In addition, a photomechanical 3D cure step may be included to help finish the material.

[0025] According to some embodiments, an exemplary cartridge comprises a sorptive matrix layer comprising or consisting of ballistic gel (BG) with homogeneously distributed dye such as Fast Blue BB (FBBB). The dye is present in a concentration of 1.5-3%, e.g., 2%.

[0026] An exemplary method of on-site analysis for detection of THC by law enforcement comprises requiring a subject to exhale air into a breathalyzer so that the exhaled air contacts a multilayer cartridge including at least one layer that is a sorptive matrix and a dye contained in the sorptive matrix, wherein the dye has a colorimetric and / or luminescent response to THC that distinguishes from CBD; measuring a color or fluorescence intensity of the dye, wherein the color or fluorescence intensity correlates with a concentration of THC particles; and giving an immediate determination of whether the subject used THC within the last two hours based on the measurement.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a representative scheme of the chemical foundation of an exemplary portable THC breathalyzer device.

[0029] Figure 2 is an exemplary portable THC breathalyzer system.

[0030] Figures 3A-3D show alternative exemplary cartridges.

[0031] Figure 4 shows intensities of 10 cartridges after the addition of lOpg of A9-THC.

[0032] Figure 5 shows calibration curves of A9-THC in sample cartridges.

[0033] DETAILED DESCRIPTION

[0034] Figure 1 is a representative scheme of the chemical foundation of an exemplary THC breathalyzer device. Some of the THC particles (e.g., A9-THC) generated during smoking marijuana is carried by aerosolized particles and deposited on the lung tissues. These particles can be removed by exhalation and be detected in breath, typically up to two hours from the cessation of last marijuana use. Thus, the detection of A9-THC using this device is based on the capacity of the breathalyzer 101 is configured with a cartridge that reacts with the particles still deposited in the superior tract of the subject which can detach during exhalation and exit the body in the exhaled breath. Such particles have been found to be present in detectable levels in exhaled breath for an interval of time of, for example, 30 minutes to 2 hours after smoking one marijuana cigarette. An exemplary cartridge react positively to a concentration of at least as low as 0.01 pg of A9-THC. Achieving lower concentrations is extremely important as the concentration of A9-THC in exhaled air is described to be in the range of 1 ng / 30 L of exhaled air.

[0035] Inside the breathalyzer device 101 is a cartridge comprising a multilayer structure including at least one layer that is a sorptive matrix and a dye contained in the sorptive matrix. The dye has a colorimetric response to THC that is distinguishable from the response, if any, to CBD. The cartridge is placed in contact with exhaled breath, and any THC particles present in the exhaled air of the subject are corresponding exposed to the dye. The dye and THC have a colorimetric reaction. The reaction between the A9-THC (and / or other THC isomers) and the dye gives a response that can be colorimetric (appearance or color change) and / or luminescent (light emission against UV irradiation). The breathalyzer 101 and / or auxiliary devices which together form a breathalyzer system is configured for measuring the color of the used cartridge (e.g., spectrophotometrically) and a relationship between color intensity and concentration is made. A result is given via an output device such as a screen.

[0036] Figure 2 is a diagram of an exemplary portable THC breathalyzer system 200. The breathalyzer 210 functions as an air collector (air collection system) for capturing exhaled breath and ensuring exposure of the breath with a THC sensitive cartridge. A mouthpiece 211 is connected to a cartridge receptor chamber 213 via a spacer 212. A cartridge 220 is insertable into the cartridge receptor chamber 213 preceding use and removable from the chamber 213 after use. During use the cartridge is fixed at the end of the spacer 212 where the THC particles will collide and react. While the cartridge 220 is installed, the subject breaths into the mouthpiece 211. The breathalyzer 210 may be configured without outlets so that a positive pressure forms within spacer 212 and against the cartridge 220 inside the chamber 213 for the duration of the exhalation. The air exiting the lungs is approximately body temperature (e.g., 37°C). When the contents of the exhaled air come into contact with the cartridge surface, which is cooler, some condensation may occur which can be advantageous. Any THC particles in the breath react with the reagent (e.g., THC sensitive dye) in the cartridge surface layer 221.

[0037] The reaction between THC and dye of the cartridge obeys the Lambert-Beer Law, and the hue / amount / intensity of color formed is directly proportional to the intensity of the color formed. In the case of an exemplary dye like Fast Blue BB (FBBB), the greater the amount of THC, the darker a resulting red color, for example. After a predetermined fixed duration of exhalation, the cartridge receptor chamber 213 is opened, and the used cartridge 220 may be removed. The cartridge 220 is then analyzed with a portable imaging system 230 (not shown to scale in Figure 2) such as a portable miniaturized scanner. The image acquisition method eliminates or at least minimizes shadow and color scheme variation from one image to the next.

[0038] The imaging system 230 may comprise, for example, a controller 231 (e.g., one or more processors, e.g., a microcontroller) and at least one camera 232 sensitive to the visible light spectrum. An exemplary imaging system 230 may further comprise a blackout box / chamber 233 configured to shield at least the surface layer 221 of the cartridge 220 from ambient light during imaging and (ii) a light source 234 which provides the only illumination of the surface layer 221 of the cartridge 220 during image capture. The chamber 233 may be configured to hold the cartridge still (no movement) during imaging. The chamber 233 may be completely enclosed during use. An exemplary imaging system 230 may, if desired, further include a user interface 235 such as a display. The at least one controller 231 is configured to image (e.g., scan) the cartridge 220 and perform image processing of the resulting captured image. A non-limiting example of software which may be used in some embodiments for image processing is ImageJ software, for example. The controller 231 reads an intensity of the color (e.g., red color) resulting in a numerical value. The measurement is then converted to a THC concentration result by the processor 231 for output, e.g., by the display 235. In addition, or in the alternative, the system 200 may further comprise an app installed on a cellphone or other mobile device 240 of the user, and the mobile device 240 miming the special purpose software of the app may perform one or more aspects of the image processing and subsequent display of results. Some or all parts of system 230 may be configured as an auxiliary device that is connectable by wired or wireless connection to a mobile device 240. In some embodiments, the processor 231 and display 235 may be subparts of a mobile device 240. In some embodiments, the camera 232 and / or illumination source 234 may be subparts of the mobile device 240. An exemplary system 200 may be configured to detect concentrations of A9-THC in the breath at least as low as 250 parts per trillion (ppt), a challenging detection limit in the art.

[0039] Figures 3A-3D show alternative exemplary cartridges. Each cartridge 310, 320, 330, 340 comprises a multilayer structure including at least one layer that is a sorptive matrix that provides a reactive surface. The at least one layer that is a sorptive matrix may be a cover layer or top layer of the multilayer structure. Such layer may be formed as a film. At least one reagent (e.g., dye) is contained in the sorptive matrix. The reagent (e.g., dye) is spread uniformly on and / or in the reactive surface. The dye has a colorimetric and / or luminescent response to THC that distinguishes from CBD. An exemplary concentration of the dye in the sorptive matrix is 1.5-3%. For example, the dye concentration may be 2% in some embodiments. Dye concentrations which are lower than 1.5% may result in inadequate sensitivity to the low levels of THC particles typical of exhaled breath even when the breath is from a person who has recent smoked marijuana (e.g., within two hours of being tested). The signal intensity from image analysis of color (color intensity) may be too low. Dye concentrations which are higher than 3% may result in saturation of the dye in the medium resulting in poor solubility. High dye concentrations may also comprise the integrity of the matrix holding the dye.

[0040] Cartridge shape may vary among embodiments. However, a symmetrical shape, in particular a circular shape, is advantageous in some exemplary embodiments. Figures 3A-3D are shown in cross-section but may be understood as representing, for example, cross-sections taken at the center of circular / disk shaped cartridges. The cartridge 220 of Figure 2 shows a front view which may correspond with the cross-sectional view of cartridge 330 of Figure 3C, for example. The circular shape, particularly for the sorptive matrix layer(s), is particularly advantageous for achieving uniform exposure of the sorptive matrix surface to the exhaled breath of a subject in a state of use.

[0041] Figure 3A is a cartridge 310 with at least two layers 311 and 312 forming a multilayer structure. At least one layer 311 is a sorptive matrix containing at least one dye reactive to THC. The layer 312 is a support layer. Layer 312 improves physical rigidity and structural integrity of the multilayer structure.

[0042] Figure 3B is a cartridge 320 with at least two layers 321 and 322 forming a multilayer structure. At least one layer 321 is a sorptive matrix containing at least one dye reactive to THC. The layer 322 is a support layer. Layer 322 improves physical rigidity and structural integrity of the multilayer structure. Layer 322 includes a flange 323. The flange 323 may be configured to seal against a surface of a cartridge receptor chamber of an inhaler (sec Figure 2) in a state of use.

[0043] Figure 3C is a cartridge 330 with at least two layers 331 and 332 forming a multilayer structure. At least one layer 331 is a sorptive matrix containing at least one dye reactive to THC. The layer 332 is a support layer. Layer 332 improves physical rigidity and structural integrity of the multilayer structure. Layer 332 includes a flange 333. The flange 333 may be configured to seal against a surface of a cartridge receptor chamber of an inhaler (see Figure 2) in a state of use. The flange 333 also protects the edges of the layer 331. The layer 332 may be configured as a well that retains a liquid state of the layer 331 during manufacture until the layer 331 solidifies.

[0044] Figure 3D is a cartridge 340 with at least three layers 341, 342, and 343 forming a multilayer structure. One, two, or all three of the layers 341, 342, and 343 may be a sorptive matrix. In addition, or in the alternative, one, some, or all of the layers may be a support layer. Depending on the material of the sorptive matrix, a sorptive matrix layer may be self-supporting.

[0045] A sorptive matrix may be or include, for example, a chitosan-based gel, a photocured resin, or a ballistic gelatin (BG).

[0046] An exemplary sorptive matrix is ballistic gelatin (BG). Ballistic gelatin is conventionally used as a testing medium designed to simulate the effects of bullet wounds in animal muscle tissue. An exemplary ballistic gelatin is a solution of gelatin powder in water that is then permitted to cure / solidify prior to use. Ballistic gelatin (BG) is known as a stable medium with exemplary consistency.

[0047] A support layer may be or include, for example, one or more polymers. An exemplary support layer may be, for example, a polymeric resin. An exemplary polymeric resin may contain, for example, multiple polymers.

[0048] The one or more THC sensitive reagents in exemplary cartridges may be one or more dyes. Fast Blue dyes are exemplary colorimetric reagents for exemplary embodiments. Table 1 below summarizes three exemplary dyes within the Fast Blue dye family. These dyes are capable of identifying the main cannabinoids A9-THC, CBN, and CBD. The presence of these cannabinoids is confirmable by the formation of a reddish color after the reaction with the Fast Blue dye molecules. The individual detection of different respective cannabinoids is possible because each cannabinoid compound generates a specific color when in contact with the dye. In particular, FBBB produces easily distinguishable colors depending on the cannabinoid present. For CBD and CBN, orange and purple colors arc observed, respectively, while A9-THC results a red color. All these colors are distinguished using image processing software running on, for example, processor 231 or a processor of mobile device 240 (Figure 2). As a result, the identification of false positives from the presence of CBN or CBD in the breathalyzer is avoided in exemplary detection devices.

[0049] The reaction mechanism of the formation of the colored product when FBBB reacts with A9-THC is described as a four-step reaction, which starts with an acid-base reaction, in which the phenolic group from A9-THC is converted to phenolate ion through the reaction in a basic medium producing a water molecule. The phenolate anion has its negative charge stabilized by the resonance effect. Then, the electrons of the phenolate anion of A9-THC attack the electrophile, diazo group of FBBB molecule, in a slow step of the reaction, producing a nonaromatic intermediate. This compound suffers tautomerization resulting in the red color compound responsible for the positive result. As this reaction can occur with all isomers (A9- THC, A8-THC, and A10-THC), the colorimetric test of embodiments which exclusively employ FBBB as the THC sensitive dye does not distinguish among these THC isomers. Alternative embodiments which use a dye other than FBBB may employ one or more reagents (e.g., dyes) which do distinguish among different THC isomers for applications in which this level of differentiation is desired.

[0050] Table 1: Chemical characteristics of Fast Blue B, Fast Blue BB, and Fast Blue RR. layer is prepared of a stiff substantially inflexible material such as a polymeric substrate. The polymeric substrate may be or include one or more photocured resins, for example. Multiple support layers may be formed together to reinforce one another. At least one THC sensitive reagent (e.g., dye) is dissolved / mixed in a liquid preparation of sorptive matrix, for instance a gel solution. The combination is mixed until homogeneous, that is, the dye is uniformly distributed within the gel solution. Hot temperatures are avoided as excessive temperatures may degrade / decompose the dye molecules. The homogeneous mixture is arranged on top of the supporting substrate layer(s). If necessary temporary walls are provided to retain the gel solution until it sets. The gel is permitted to set (solidify), after which any temporary liquid retention walls are removed, if applicable. The support substrate material and sorptive matrix are configured so that the layers remain together, e.g., the gel remains adhered to the substrate after solidification. The completed multilayer structure may then be sealed in a water impermeable (and preferably water vapor impermeable) packaging to maximize the shelf life of the gel and prevent exposure to environmental particles until the cartridge is ready for use. In some embodiments, a completed multilayer cartridge structure may be inserted into / attached to an air collection system (see, e.g., breathalyzer 210 of Figure 2) and the breathalyzer with preloaded cartridge are sealed together in packaging.

[0051] EXAMPLE 1

[0052] This Example describes experimental testing of a cartridge the outer layer of which was a ballistic gelatin with 2% Fast Blue BB for the detection of THC.

[0053] Validation procedures were performed according to the ANSI / ASB 036 Standard Practices for Method Validation in Forensic Toxicology. A validation parameter to be evaluated was the linearity of the reaction. Preliminary results showed the capacity of the cartridge to react positively to a concentration of 0.01 pg of A9-THC. In addition, the BG cartridge was shown to be reproducible in a test of 10 cartridges (Figure 4).

[0054] Preliminary stability tests showed that the cartridge was stable at room temperature for at least one month. Also, the initial validation parameters showed a linear correlation between the THC concentration and the signal obtained (Figure 5). The calibration curve was prepared using different concentrations of A9-THC ranging from 5 to 100 ng / mL of the solution, in each cartridge. Standards were analyzed in triplicate. The solution was left for 15 minutes to react and the color intensity was immediately read using the ImageJ software. The intensities obtained were plotted against the A9-THC concentrations.

[0055] Some embodiments of the present invention may be a system, a device, a method, and / or a computer program product. A system, device, or computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention, e.g., processes or parts of processes or a combination of processes described herein.

[0056] The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. Processes described herein, or steps thereof, may be embodied in computer readable program instructions which may be paired with or downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device.

[0057] Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Java, Python, Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.

[0058] Aspects of the present invention are described herein with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer readable program instructions and in various combinations.

[0059] These computer readable program instructions may be provided to one or more processors of one or more general purpose computers, special purpose computers, or other programmable data processing apparatuses to produce a machine or system, such that the instructions, which execute via the processor(s) of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function / act specified in the flowchart and / or block diagram block or blocks.

[0060] The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0061] Where a range of values is provided in this disclosure, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range, is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges and are also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the invention.

[0062] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, representative illustrative methods and materials are described.

[0063] It is noted that, as used herein and in the appended claims, the singular forms

[0064] “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation.

[0065] As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. Any recited method can be carried out in the order of steps recited or in any other order which is logically possible. Alternative methods may combine different elements of specific detailed methods described above and in the figures.

[0066] While exemplary embodiments of the present invention have been disclosed herein, one skilled in the art will recognize that various changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

Claims

AMENDED CLAIMS received by the International Bureau on 10 July 2025 (10.07.2025)What is claimed is:

1. A cartridge for use in a THC breathalyzer, comprising a multilayer structure including at least one layer that is a sorptive matrix; and a dye contained in the sorptive matrix, wherein the dye has a colorimetric and / or luminescent response to THC that distinguishes from CBD.

2. The cartridge of claim 1, wherein concentration of the dye in the sorptive matrix is 1.5-3%.

3. The cartridge of claim 1, wherein the multilayer structure further comprises a polymer substrate that supports the sorptive matrix.

4. The cartridge of claim 1, wherein the dye is a Fast Blue dye.

5. The cartridge of claim 1, wherein the dye is Fast Blue BB (FBBB).

6. The cartridge of claim 1 , wherein an intensity of color of the dye is directly proportional to concentration of THC particles.

7. The cartridge of claim 1, wherein the dye is configured for detection of THC and its derivatives.

8. The cartridge of claim 1, wherein the dye is configured for detection of multiple THC isomers.

9. A breathalyzer for detecting recent use of THC, comprising a multilayer cartridge including at least one layer that is a sorptive matrix; and a dye contained in the sorptive matrix, wherein the dye has a colorimetric and / or luminescent response to THC that distinguishes from CBD.

10. The breathalyzer of claim 9, further comprising a cartridge receptor chamber configured to receive the multilayer cartridge; and a mouthpiece connected to the cartridge receptor chamber.

11. The breathalyzer of claim 9, wherein concentration of the dye in the sorptive matrix is 1.5- 3%.

12. The breathalyzer of claim 9, wherein the multilayer structure further comprises a polymer substrate that supports the sorptive matrix.

13. The breathalyzer of claim 9, wherein the dye is a Fast Blue dye.

14. The breathalyzer of claim 9, wherein the dye is Fast Blue BB (FBBB).

15. The breathalyzer of claim 9, wherein an intensity of color of the dye is directly proportional to concentration of THC particles.

16. The breathalyzer of claim 9, wherein the dye is configured for detection of THC and its derivatives.

17. The breathalyzer of claim 9, wherein the dye is configured for detection of multiple THC isomers.

18. A method of on-site analysis for detection of THC by law enforcement, comprising requiring a subject to exhale air into a breathalyzer so that the exhaled air contacts a multilayer cartridge including at least one layer that is a sorptive matrix and a dye contained in the sorptive matrix, wherein the dye has a colorimetric and / or luminescent response to THC that distinguishes from CBD; measuring a color or fluorescence intensity of the dye, wherein the color or fluorescence intensity correlates with a concentration of THC particles; andgiving an immediate determination of whether the subject used THC within the last two hours based on the measurement.

19. The method of claim 18, wherein the dye is a Fast Blue dye.

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