Nanopore Scattering Detection for Fast Parallel Analyte Sensing
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Solution Overview
Problem
Existing nanopore sensing methods face challenges in electrically addressing multiple nanopores, require high salt concentrations, and are limited by fluorescence-based detection techniques such as photobleaching and complex equipment, making them difficult to miniaturize and slow for fast analyte discrimination.
Innovation Solution
A method using a light-scattering constituent with a different refractive index than the medium, generating a flux through a nanopore, and illuminating the vicinity to detect scattering signals as analytes move, allowing for individual nanopore measurement without electrical addressing and avoiding photobleaching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fluorescence-based detection is used to detect analytes through nanopores, then detection sensitivity can be achieved, but the method requires complex equipment (filter assemblies, cameras, high numerical aperture optics) that is difficult to miniaturize and has slow acquisition rates limited to around 100 μs per fluorophore
Solution Approach 1:
The patent replaces fluorescence-based optical detection with Raman scattering-based detection. This substitution eliminates the need for complex filter assemblies, high numerical aperture optics, and cameras required for fluorescence detection. The Raman scattering method uses a simpler optical configuration that can be more easily miniaturized while achieving comparable or superior detection sensitivity for single-molecule discrimination.
Solution Approach 2:
The patent changes the detection parameter from fluorescence emission to Raman scattering signal. By measuring the inelastic scattering of light (Raman effect) instead of fluorescent emission, the system achieves faster acquisition rates and reduced equipment complexity. The Raman scattering signal provides sufficient contrast for single-molecule discrimination without requiring the complex optical filtering and detection systems needed for fluorescence.
2Measurement precision
If fluorescence-based detection is used for single-molecule discrimination, then analyte detection is possible, but the acquisition rate is limited to around 100 μs per fluorophore due to photon flux limits, preventing discrimination of faster analyte events
Solution Approach 1:
The patent replaces fluorescence detection with Raman scattering detection to overcome the photon flux limitation. Raman scattering provides a different signal generation mechanism that enables faster acquisition rates, allowing discrimination of analyte events occurring on sub-100 μs timescales while maintaining single-molecule discrimination capability.
3Measurement precision
If electrically detecting ionic currents through nanopores is used, then analyte interaction can be measured, but each nanopore in an array needs to be individually electrically addressable, complicating parallelization
Solution Approach 1:
The patent replaces electrical detection of ionic currents with optical detection of Raman scattering signals. This substitution allows nanopores to be optically addressed and measured in parallel without requiring individual electrical addressing of each pore. Multiple nanopores can be illuminated and detected simultaneously using a single optical path, enabling straightforward parallelization and array fabrication.
4Power
If high salt concentrations are used to generate sufficient ionic currents for analyte discrimination, then current signal magnitude is adequate, but the high salt interacts or interferes with the analytes present
Solution Approach 1:
The patent replaces electrical current measurement with optical Raman scattering measurement. This substitution eliminates the requirement for high salt concentrations to generate sufficient ionic current. The Raman scattering signal generation does not depend on ionic conductivity, allowing analyte detection in low-salt or physiological buffer conditions that do not interfere with analyte structure or function.
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 parallelization and miniaturization of nanopore sensing, with faster detection times and higher sensitivity than fluorescence-based methods, capable of detecting analytes on a microsecond scale without requiring complex optical equipment.
Implementation Method 1
the medium in the vicinity of the nanopore is illuminated with one or more light sources thus resulting in the generation of a scattering signal as light is scattered from the constituent
Implementation Method 2
contacting the medium with a nanopore such that a flux of the light-scattering constituent is generated through the nanopore
Data Source
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AI summary
The invention provides methods of optically detecting an analyte in a medium as the analyte moves with respect to a nanopore. The analyte may be, for example, a biological molecule such as a polynucleotide or polypeptide. Systems and apparatuses for carrying our such methods are also provided.