Collection Substrate for Trace Analyte Preconcentration
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Solution Overview
Problem
Current field-portable spectroscopic tools, such as Hazmat ID and FTIR spectrometers, face challenges in analyzing trace residues on surfaces due to interference from the surface itself and require direct contact with the analyte, limiting their ability to detect analytes on rough or porous surfaces and in low concentrations.
Innovation Solution
The development of 'smart wipes' with collection substrates designed to capture and concentrate target analytes using materials with high affinity for the analytes, allowing for interference-free analysis through spectroscopy without the need for direct contact, using techniques like sorption, chemical reactions, or physical abrasion, and enabling transfer to other substrates for further analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If ATR-based measurement is used to detect analytes on surfaces, then the measurement can be performed in the field with portable equipment, but the surface must be smooth and flat within 1-20 micrometers of the ATR crystal surface, limiting detection on rough or porous surfaces
Solution Approach 1:
The patent introduces a collection substrate as an intermediary between the rough/porous surface and the ATR crystal. The collection substrate first captures analytes from the surface through sorption or absorption, then transfers them to the ATR crystal for measurement. This mediator enables detection on surfaces that would otherwise be inaccessible to direct ATR measurement.
Solution Approach 2:
The collection substrate performs preliminary capture and concentration of analytes from the surface before transfer to the ATR crystal. This preliminary action accumulates sufficient analyte material on the collection substrate to enable detection, even when the original surface is rough or porous and cannot be directly measured.
2Measurement precision
If ATR measurement is used to detect trace residues on surfaces, then the instrument can identify substances, but the surface optical signature dominates the spectrum and obscures trace level measurement
Solution Approach 1:
The collection substrate extracts and concentrates the target analyte from the surface mixture, separating it from the surface material that causes optical interference. By taking out only the analyte of interest and concentrating it on the collection substrate, the harmful optical signature of the surface is eliminated from the measurement.
Solution Approach 2:
The collection substrate acts as an intermediary that isolates the analyte from the surface. It captures the analyte through sorption or absorption, then transfers it to the ATR crystal, preventing the surface optical signature from interfering with the trace level measurement.
3Reliability
If direct contact ATR measurement is used, then the analyte must contact the ATR crystal surface within the evanescent field, but this limits detection to smooth surfaces and prevents measurement of analytes on rough or porous surfaces
Solution Approach 1:
The collection substrate serves as a mediator that bridges the gap between rough/porous surfaces and the ATR crystal. It captures analytes from surfaces regardless of texture through sorption or absorption, then transfers them to the ATR crystal for reliable measurement, eliminating the need for direct contact between the analyte and crystal.
Solution Approach 2:
The collection substrate performs preliminary capture of analytes from the surface before transfer to the ATR crystal. This preliminary action ensures sufficient analyte is collected regardless of surface texture, enabling reliable detection on rough or porous surfaces that would otherwise be inaccessible.
4Ease of operation
If conventional swabs are used to collect analytes for ATR analysis, then the swab serves as a sorbent to hold bulk solvent, but this approach lacks selectivity and cannot effectively concentrate trace analytes
Solution Approach 1:
The collection substrate is designed with specific local properties tailored to the target analyte, such as molecular imprinting sites, tailored surface energy, or specific binding sites. This local quality provides high selectivity and affinity for the analyte, enabling effective concentration of trace substances unlike conventional non-selective swabs.
Solution Approach 2:
The collection substrate may utilize composite materials combining sorbent properties with selective binding capabilities. This composite structure enables both the simplicity of a single-material swab approach and the advanced selectivity/concentration capability needed for trace analyte detection.
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 efficient and selective capture and concentration of analytes for interference-free detection using spectroscopy, improving the ability to analyze trace residues on surfaces and in low concentrations, enhancing the effectiveness of field detection systems.
Implementation Method 1
The collection substrate can react with or capture the target analyte through sorption, chemical reaction, or through physical abrasion and entrapment of the surface bound analyte
Implementation Method 2
an optical spectrometer producing an optical beam that probes the target analyte on the substrate. For example, the spectrometer can be a Fourier transform, dispersive, filterometric, or laser based spectrometer
Implementation Method 3
The Hazmat ID is a ruggedized version of a commercially available Attenuated Total Reflectance (ATR) infrared spectrometer
Implementation Method 4
the target analyte must contact the ATR crystal surface, or minimally reside within 1-20 micrometers of the ATR crystal surface so as to be within the evanescent field extending beyond the crystal surface
Data Source
AI summary
An apparatus for capturing a target analyte in advance of performing spectroscopic analysis to determine the existence of the target analyte from a source contacted with a collection substrate. The collection substrate is fabricated of a material selected to have an affinity for the target analyte, sufficiently transparent in a spectral region of interest and capable of immobilizing the target analyte thereon in a manner that limits scattering sufficient to obscure spectral analysis. The collection substrate may be coated with a material selected to react with, bind to, or absorb the target analyte. The target analyte may be captured to the collection substrate by one or more of wiping, dabbing or swabbing a target analyte carrier with the collection substrate.