Electrochemical Breath Sensor for THC Detection
Solution Overview
Problem
Current methods for detecting THC in breath samples are not suitable for roadside use due to their complexity, invasiveness, and inability to provide real-time results, as they often require laboratory settings and are not effective in determining recent exposure to marijuana, which is a public safety concern given the prevalence of marijuana-related traffic accidents.
Innovation Solution
A portable, non-invasive electrochemical sensor system that uses a filter to trap THC from exhaled breath, followed by elution and immobilization on a screen-printed sensor chip for direct electrochemical detection, allowing for real-time quantification using pulse voltammetry techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If urine or blood tests are used to detect THC, then detection sensitivity is improved, but ease of operation deteriorates due to invasiveness and requirement for medical professionals
Solution Approach 1:
The invention extracts only the essential function of THC detection from complex laboratory procedures by using a portable electrochemical sensor that directly measures THC in breath condensate, eliminating the need for blood draws or urine collection and subsequent laboratory analysis
Solution Approach 2:
The invention introduces breath condensate as an intermediary medium that contains THC and can be collected non-invasively, then analyzed by a portable sensor, serving as a bridge between invasive blood/urine testing and simple breath analysis
2Measurement precision
If blood tests are used to detect active THC, then measurement precision is improved for recent use, but loss of time worsens due to immediate sample collection requirement
Solution Approach 1:
The invention performs preliminary collection of breath condensate that contains THC, which can then be analyzed immediately or stored for later analysis without compromising the detection of recent use, allowing flexible timing while maintaining accuracy
Solution Approach 2:
The invention replaces the mechanical process of blood drawing with an electrochemical sensing system that detects THC in breath condensate, eliminating the need for immediate phlebotomy while maintaining detection capability for recent use
3Measurement precision
If complex laboratory analysis methods are used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The invention extracts the core detection function from complex laboratory instruments by using a specialized electrochemical sensor that directly measures THC in breath condensate, eliminating the need for sophisticated gas chromatography-mass spectrometry systems
Solution Approach 2:
The invention employs disposable screen-printed electrodes that are inexpensive and single-use, replacing expensive, complex, and reusable laboratory instrumentation while maintaining detection accuracy
4Ease of operation
If saliva samples are collected, then ease of operation is improved compared to blood tests, but object-generated harmful factors worsen due to DNA identification risk
Solution Approach 1:
The invention extracts only the THC-containing portion of breath condensate for analysis while discarding the cellular component that would contain DNA, thereby maintaining ease of non-invasive collection while eliminating privacy infringement risks
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables rapid, sensitive, and cost-effective detection of THC at the point of collection, overcoming the limitations of existing techniques by providing immediate results suitable for roadside use and addressing the challenge of recent exposure assessment.
Implementation Method 1
providing a filter that traps THC in exhaled breath; causing a subject to exhale onto the filter, whereby at least some of the THC, if present in an exhaled breath, is trapped in the filter
Implementation Method 2
washing the filter with an eluent, whereby at least some of the THC trapped in the filter is eluted therefrom in an eluate
Implementation Method 3
directly electrochemically detecting and/or quantifying the immobilized THC
Data Source
AI summary
Method and system for detecting and/or quantifying Δ9-tetrahydrocannibinol (THC) in exhaled breath. In one embodiment, the method involves providing an electrochemical sensing element, the electrochemical sensing element including a working electrode, and also providing a filter that traps THC in exhaled breath. Next, a subject exhales onto the filter, whereby at least some of the THC, if present, is trapped in the filter. Next, the filter is washed with an eluent, whereby at least some of the THC trapped in the filter is eluted in an eluate. Next, the eluate is deposited onto the working electrode of the electrochemical sensing element, and the eluate is dried, whereby any THC present is immobilized on the working electrode. Next, an electrolytic solution is delivered to the electrochemical sensing element, and the THC immobilized on the working electrode is directly electrochemically detected and/or quantified using a pulse voltammetry technique, such as square-wave voltammetry.