Surface Plasmon Detection Substrate with Transmissive Zones
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Solution Overview
Problem
Existing surface enhanced fluorescence spectroscopy techniques face accuracy degradation due to fluorescence from labeled antibodies not binding with the detection object substance, which complicates operations and increases detection time, as removing these non-binding antibodies is cumbersome and interferes with measurement accuracy.
Innovation Solution
A detection apparatus with a substrate featuring a metal microstructure that includes a light transmissive portion and a non-light transmissive portion, where excitation light is introduced from the side opposite to the metal microstructure, generating surface plasmons and enhancing fluorescence only in the vicinity of the metal microstructure, thereby reducing noise and allowing for accurate detection without removing non-binding labeled antibodies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If labeled antibodies not binding with detection object substance are present in the measurement, then fluorescence signal is generated, but detection accuracy is degraded due to noise from non-specific binding
Solution Approach 1:
The substrate surface is segmented into light transmissive portions and non-light transmissive portions. The metal microstructure is selectively formed only on the non-light transmissive portions, creating spatially separated regions where surface plasmon resonance occurs only at specific locations, thereby confining the enhancement effect to reduce noise from non-binding antibodies
Solution Approach 2:
Different regions of the substrate are given different optical properties: light transmissive portions allow light passage while non-light transmissive portions (covered with metal film) generate surface plasmons. This local differentiation ensures that fluorescence enhancement occurs only in specific localized areas where metal microstructures are present, reducing background noise
2Measurement precision
If removal operations are performed to eliminate non-binding labeled antibodies, then detection accuracy is improved, but operations become complicated and detection time increases
Solution Approach 1:
Instead of removing non-binding antibodies through complex operations, the invention converts the harmful background fluorescence into a beneficial signal by using surface plasmon resonance to selectively enhance only the fluorescence from antibodies bound to metal microstructures. The non-binding antibodies present in the solution do not generate significant signal because they are not in proximity to the metal structures that generate plasmon enhancement
3Ease of manufacture
If excitation light is irradiated from the same side as metal microstructure, then fluorescence can be detected, but light transmissive metal structure is required which complicates manufacturing
Solution Approach 1:
Instead of irradiating light from the same side as the metal microstructure (which would require transparent metal structures), the invention inverts the configuration by irradiating light from the opposite side of the substrate. The light passes through the substrate and excites surface plasmons in the metal microstructures, which then enhance fluorescence that can be detected from the original side, eliminating the need for transparent metal structures
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
This approach enhances the signal-to-noise ratio of the detected fluorescence, improving the accuracy of detecting the detection object substance without the need for complex optical systems or removal operations, and simplifies the detection process by limiting the irradiation range of excitation light to the vicinity of the metal microstructure.
Implementation Method 1
the metal microstructure generating a surface plasmon by being irradiated with excitation light
Implementation Method 2
fluorescence generated from the fluorescent material in response to irradiation of the excitation light
Data Source
AI summary
A detection apparatus includes: a substrate; a metal nanostructure on a surface of the substrate and on which immobilized antibodies having a property of binding with a detection object substance are immobilized, the metal microstructure generating a surface plasmon by being irradiated with excitation light; an introducer that introduces labeled antibodies having a property of binding with the detection object substance and labeled with a fluorescent material, and a test solution containing the detection object substance into the metal nanostructure; a light source that irradiates the metal nanostructure with the excitation light from the back surface side of the substrate; and a photodetector that detects the detection object substance based on fluorescence generated from the fluorescent material in response to irradiation of the excitation light. The metal nanostructure includes a light transmissive portion that transmits, to the surface side of the substrate, the excitation light emitted from the back surface side thereof.