Paper Microfluidic PFAS Detection via Capillary Flow Change
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Solution Overview
Problem
Current methods for detecting per- and polyfluoroalkyl substances (PFAS) are complex, costly, and lack specificity, particularly in detecting cationic, zwitterionic, or non-ionic PFAS molecules, with limitations in sensitivity and requiring extensive laboratory analysis.
Innovation Solution
A composition and paper microfluidic chip utilizing cellulose fibers and biomolecules, such as L-lysine, bovine serum albumin (BSA), and casein, that interact with PFAS through charge, hydrophobic, and hydrogen bonding interactions to alter capillary flow rates for detection, enabling sensitivity down to 70 ppt (70 fg/μL).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If HPLC-MS/MS is used for PFAS detection, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the detection function from complex laboratory equipment (HPLC-MS/MS) and implements it in a simplified paper-based microfluidic device. The paper chip contains integrated reagent zones that perform separation and detection functions, eliminating the need for expensive external equipment while maintaining detection capability at EPA advisory levels.
Solution Approach 2:
The patent introduces paper-based microfluidic channels and reagent zones as intermediaries between the sample and detection. These intermediaries perform the complex separation and analysis functions that would otherwise require HPLC-MS/MS equipment, translating complex laboratory functions into a simple portable device.
2Measurement precision
If HPLC-MS/MS is used for PFAS detection, then measurement precision is improved, but loss of time increases
Solution Approach 1:
The patent performs preliminary separation and concentration actions within the paper chip itself before detection. The microfluidic channels pre-separate PFAS compounds from the sample matrix and concentrate them at detection zones, eliminating the need for time-consuming post-sample preparation steps required by HPLC-MS/MS.
Solution Approach 2:
The patent merges multiple laboratory functions (sample introduction, separation, concentration, and detection) into a single integrated paper-based device. This consolidation eliminates the sequential time delays between separate laboratory operations, enabling rapid total analysis time while maintaining detection precision.
3Ease of operation
If methylene blue is used for PFAS detection, then ease of operation is improved, but measurement precision deteriorates
Solution Approach 1:
The patent applies local quality by creating specialized zones within the paper chip with different functional properties. Reagent zones contain specific chemicals (e.g., methylene blue, other indicators) optimized for detecting particular PFAS compounds, while separation zones and sample zones have different properties. This zoned approach maintains operational simplicity while achieving EPA-level detection sensitivity through localized chemical interactions.
4Measurement precision
If molecularly imprinted polymer is used for PFAS detection, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent uses paper-based microfluidic structures that copy or replicate the separation and detection functions of complex MIP-based systems. The paper channels and reagent zones simulate the selective binding and detection capabilities of molecularly imprinted polymers through simpler chemical interactions, achieving comparable detection precision without the complexity of MIP synthesis and integration.
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
The method provides rapid, economical, and specific detection of PFAS, including PFOA, by analyzing flow rate changes, overcoming limitations of existing techniques in sensitivity and specificity.
Implementation Method 1
the one or more biomolecules interact with the one or more environmental toxicants by charge interaction, hydrophilic interactions, hydrophobic interactions, affinity interactions, hydrogen bonding, electrostatic repulsion, electrostatic attraction, Van der Waals forces
Implementation Method 2
the one or more biomolecules interact with the one or more environmental toxicants by charge interaction, hydrophilic interactions, hydrophobic interactions, affinity interactions, hydrogen bonding
Implementation Method 3
the one or more biomolecules interact with the one or more environmental toxicants by charge interaction, hydrophilic interactions, hydrophobic interactions, affinity interactions, hydrogen bonding
Implementation Method 4
detecting environmental toxicants by utilizing competitive interactions during capillary action
Data Source
AI summary
Disclosed herein are aspects of a composition for detecting environmental toxicants such as, but not limited to, perfluorinated-alkyl substance, perfluorooctanoic acid, and the like. The composition allows for the rapid, sensitive detection of perfluorinated-alkyl substances (PFAS) by utilizing the competitive interactions during capillary action. The composition comprising one or more cellulose fibers; and one or more biomolecules associated with the one or more cellulose fibers, wherein the composition is configured so that when the composition contacts the liquid sample, the one or more biomolecules disassociate from the one or more cellulose fibers by interacting with the one or more environmental toxicants thereby decreasing the flow of the liquid sample comprising one or more environmental toxicants. A system for using the composition is also disclosed along with a method of using the paper microfluidic chips and a method making the paper microfluidic chip.