Localized Surface Plasmon Resonance Sensor with Orthogonal Nanorods
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Solution Overview
Problem
Conventional localized surface plasmon sensors require movement of a light source or substrate to maintain measurement accuracy, which can decrease accuracy due to positioning errors.
Innovation Solution
A method using an apparatus with a cell containing a first and second region, where metallic nanorods with antibodies and blocking substances are aligned orthogonally, and polarized light is rotated to calculate antigen concentration without moving the light source or substrate, utilizing the difference in localized surface plasmon resonant wavelength shifts between the regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If light source or substrate is moved to maintain measurement accuracy, then measurement accuracy is improved, but positioning errors occur
Solution Approach 1:
The patent replaces the mechanical movement system (moving light source or substrate) with an optical field rotation system. By rotating the polarization direction of light and the orientation of metallic nanorods, the system achieves measurement of different regions without physical displacement, thereby eliminating positioning errors while maintaining measurement accuracy.
Solution Approach 2:
The patent transitions from spatial dimension (moving light source or substrate in physical space) to polarization dimension (rotating light polarization and nanorod orientation). This dimensional change allows the system to access different measurement regions by changing the orientation state rather than physical position, resolving the contradiction between measurement accuracy and positioning reliability.
2Adaptability or versatility
If light source or substrate is moved to measure different regions, then antigen concentration can be determined, but measurement accuracy decreases due to positioning errors
Solution Approach 1:
The patent performs preliminary alignment of metallic nanorods in specific orientations and pre-sets the polarization direction of incident light. By preparing the optical system and sensor structure in advance with predetermined orientations, the system can measure different regions (signal region and reference region) by simply rotating the polarization angle without requiring dynamic positioning adjustments during measurement, thus maintaining accuracy while achieving versatility.
3Measurement precision
If conventional localized surface plasmon sensor is used, then antigen concentration can be detected, but light source or substrate movement is required
Solution Approach 1:
The patent merges the signal region and reference region into a single substrate with metallic nanorods arranged in different orientations. By combining both measurement regions and their respective nanorod structures into one integrated sensor, the system eliminates the need for separate substrates or moving parts, simplifying the overall device structure while maintaining the ability to perform differential measurements for accurate antigen 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
This approach improves measurement accuracy by eliminating the need for light source or substrate movement, allowing precise antigen concentration determination without positional errors.
Implementation Method 1
surface plasmon resonance occurs by free electrons in a metal interacting with electromagnetic waves (light)... localized surface plasmon resonance... A sensor using propagating surface plasmon resonance has, for example, a triangular prism... When light enters into the thin metallic film from a certain angle, propagating surface plasmon resonance occurs
Implementation Method 2
a polarizing plate for polarizing light emitted from the light source... transmitting polarized light parallel to the long-axis direction of the plurality of first metallic nanorods... rotating at least either one of the polarizing plate or the cell such that polarized light which has passed through the polarizing plate is parallel to the long-axis direction of the plurality of second metallic nanorods
Implementation Method 3
antibodies are immobilized on the surface of the thin metallic film... antibodies that bond to biomolecules are immobilized on particulates formed in one region... the antigen and the antibody react with and bond to each other
Data Source
AI summary
A biogenic substance concentration measuring apparatus includes an optical measuring apparatus for measuring optical properties of a first substrate and a second substrate by using a cell for biogenic substance concentration measurement that includes: the first substrate on which a plurality of first metallic nanorods, each of which is modified with a substance that bonds specifically to a test substance, are immobilized such that the long axes thereof are aligned in the same direction; and the second substrate on which a plurality of second metallic nanorods, each of which is modified with a blocking substance, are immobilized such that the long axes thereof are aligned perpendicularly to the long axes of the first metallic nanorods on the first substrate, and calculates a biogenic substance concentration with high accuracy from the optical properties.