Systems and methods using Surface-Enhanced Raman Spectroscopy for detecting tetrahydrocannabinol
Inventors
Stoll, Jeffrey A. • Anekal, Samartha G. • Mohan, Karan
Assignees
Triple Ring Technologies Inc • Hound Labs Inc
Publication Number
US-11933731-B1
Publication Date
2024-03-19
Expiration Date
2041-05-12
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Abstract
The present disclosure relates to using Surface-Enhanced Raman Spectroscopy (SERS) for detecting analytes in samples. Uses can include, for example, detection of tetrahydrocannabinol (THC) using SERS, as well as apparatuses and systems to implement such detection methods.
Core Innovation
The invention provides systems, apparatuses, and methods that utilize Surface-Enhanced Raman Spectroscopy (SERS) for detecting analytes in samples, particularly tetrahydrocannabinol (THC) in breath samples. The core approach is to use SERS-active substrates, often incorporating metal nanostructures like gold or silver nanoparticles, to greatly enhance Raman signals of target analytes, enabling trace and even single molecule detection of THC. Unique apparatus and systems are described, including hand-held breath sample devices with specialized capture sites and fluidic and optical interfaces for efficient sample collection and analysis.
The problem addressed is the lack of reliable methods and devices for determining levels of cannabinoid compounds, such as THC, in a subject's sample, especially in breath, which is challenging due to the low concentrations and non-volatile nature of these analytes. Existing methods focused on saliva, urine, or blood are less suited for point-of-care or rapid impairment assessment, and affinity-based breath collection is inefficient for non-volatile analytes. The present technology overcomes these limitations by enabling the detection and quantification of THC from breath samples using mechanical capture methods coupled with optical detection, increasing both sensitivity and specificity.
The core system includes a housing with a cartridge interface for a SERS-active substrate that has capture sites for collecting breath sample analytes. The SERS-active substrate is designed to capture aerosol droplets from breath via inertial impaction and facilitate enhanced Raman signal acquisition when exposed to laser light. The method further involves determining analyte amounts by comparing detected Raman signals to established thresholds correlated with impairment-related THC levels, providing immediate, label-free, and direct detection capability. The system may also optionally include means for wireless data transmission and integration into broader analysis or reporting systems.
Claims Coverage
There are three independent claims in this patent, each outlining distinct inventive features pertaining to a handheld apparatus, a method, and a system for THC detection in breath using SERS.
Handheld breath sample apparatus with SERS-active substrate and threshold correlation
A handheld breath sample apparatus includes a housing with a cartridge interface designed to mechanically interface with a cartridge containing a SERS-active substrate having one or more capture sites for a breath sample. The apparatus further includes a detection device optically coupled to the SERS-active substrate to detect emitted Raman signals and correlate them with a threshold level of THC. The threshold is defined as being correlated with the average amount of THC in breath between 2 and 3 hours after inhalation.
SERS-based method for THC detection in breath with threshold comparison and indication
A method using SERS for detecting THC in a breath sample, comprising: determining the amount of THC captured from a breath sample using a SERS-active substrate with one or more capture sites; comparing the determined THC amount to a threshold level for THC in breath; and indicating whether the determined THC amount exceeds the threshold. The threshold is correlated with the average amount of THC in breath between 2 and 3 hours post-inhalation.
System using SERS for THC breath detection with specific instrumentation and thresholding
A system for detecting THC in a breath sample using SERS, comprising: an excitation laser configured to excite a SERS-active substrate with one or more capture sites for the breath sample; a high sensitivity spectrometer for collecting one or more Raman signals from the capture sites; and a detector electrically connected to the spectrometer. The system ensures that the one or more Raman signals are directly proportional to a threshold level of THC captured in the breath sample, with the threshold level correlated with the average amount of THC in breath between 2 and 3 hours after inhalation.
The inventive features claim a unique handheld apparatus, a method of detection, and a system each utilizing SERS for capturing and detecting THC in breath, applying a defined threshold correlated to impairment metrics, and specifying mechanical and optical configurations that enable trace-level and single molecule sensitivity.
Stated Advantages
Enables highly sensitive detection of THC in breath samples, up to single molecule sensitivity, through significant SERS signal enhancement.
Provides label-free, direct detection of analytes, increasing specificity by relying on molecular signature Raman spectra rather than labels or tags.
Offers point-of-care format with mechanical sample capture and rapid analysis, maximizing use of concentrated samples and enabling immediate results.
Facilitates detection and quantification of THC at levels directly correlated with impairment windows, supporting more reliable impairment assessment.
Documented Applications
Detection of tetrahydrocannabinol (THC) in breath samples, particularly for impairment assessment.
Detection of other cannabinoids and related analytes in breath samples, such as cannabinol (CBN), cannabidiol (CBD), and THC metabolites.
Integration with systems for detection of airborne substances including controlled substances, disease state markers, and viruses in breath.
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