Optical-Waveguide Sensor Chip for Low-Volume Analyte Detection
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Solution Overview
Problem
Conventional immunological assays require large volumes of analyte samples and lengthy procedures, making it difficult to monitor changes over time and necessitating the sacrifice of animals for each test, especially when dealing with small animals like rats.
Innovation Solution
An optical-waveguide sensor chip with a first substance immobilized on its surface and fine particles dispersed with a second substance, allowing for specific reactions with analyte substances, reducing the sample volume required and simplifying the measurement process by detecting optical changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional immunological assays are used, then measurement accuracy is achieved, but large sample volume (5-25 μL) and long procedure time (several hours) are required
Solution Approach 1:
The patent combines multiple assay functions (capture antibody binding, detection antibody binding, and optical signal generation) into a single integrated sensor chip structure. The optical waveguide integrates signal transmission and detection, eliminating the need for separate measurement steps and reducing total sample volume required.
Solution Approach 2:
The patent replaces conventional mechanical/chemical detection methods with optical field-based detection using evanescent waves. This substitution enables highly sensitive detection with minimal sample volume, as the optical field interacts directly with bound molecules without requiring large volumes for colorimetric or other chemical assays.
2Reliability
If conventional immunological assays are used, then reliable detection is achieved, but complex procedures with multiple reagent additions and washes are required
Solution Approach 1:
The patent pre-immobilizes capture antibodies on the sensor chip surface before sample application. This preliminary preparation eliminates the need for in-assay antibody additions and washes, simplifying the procedure while maintaining reliable detection through pre-configured specific binding sites.
Solution Approach 2:
The sensor chip is designed as a universal platform that can detect multiple analytes by simply changing the immobilized capture antibody, without requiring different hardware or procedural setups. The optical detection system universally detects any analyte-antibody complex formed on the chip surface.
3Measurement precision
If conventional immunological assays are used, then sufficient detection sensitivity is achieved, but long reaction times (almost one hour per reaction step) are required
Solution Approach 1:
The patent changes the detection parameter from conventional bulk solution measurement to surface-based evanescent field interaction. This parameter change enables rapid detection because the evanescent field is confined to a thin region near the waveguide surface, allowing quick establishment of equilibrium binding without requiring long incubation times for bulk solution mixing and reaction.
4Measurement precision
If small animals like rats are tested using conventional assays, then necessary test data is obtained, but one animal must be sacrificed for each examination
Solution Approach 1:
The sensor chip enables repeated measurements from the same small animal sample by requiring only minimal sample volume (1 μL). The same blood sample can be used for multiple sequential measurements of different analytes or for monitoring changes over time, eliminating the need to sacrifice separate animals for each test.
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 quantitative determination of analyte concentrations using a small analyte sample volume (10 μL or less) in a single operation, reducing procedural time and animal sacrifices, while allowing for precise monitoring of changes in analyte concentrations.
Implementation Method 1
an optical waveguide having a first substance immobilized on the surface thereof
Implementation Method 2
When light is made to propagate through the optical waveguide, an evanescent field is generated in a region close to the surface of the optical waveguide
Data Source
AI summary
An optical-waveguide sensor chip includes an optical waveguide having a first substance immobilized on the surface thereof, the first substance being specifically reactive with an analyte substance, and fine particles dispersed on the optical waveguide and having a second substance immobilized on the surface thereof, the second substance being specifically reactive with the analyte substance.