Ratiometric SERS Sensor for Glucose Detection
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Solution Overview
Problem
Conventional surface-enhanced Raman spectroscopy methods face challenges in accurately detecting analytes like glucose within biological bodies due to variations in the measurement environment, such as refractive index and excitation light intensity, which affect the intensity of surface-enhanced Raman-scattered light.
Innovation Solution
A detection method and system utilizing a sensor chip with a metal pattern and two substances, where one substance generates Raman-scattered light intensity that remains constant and the other varies with analyte concentration, allowing for precise detection by calculating a ratio of these intensities to compensate for environmental changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If surface-enhanced Raman spectroscopy is used to detect analytes in biological bodies, then detection sensitivity is improved, but measurement precision deteriorates due to environmental variations
Solution Approach 1:
The patent introduces a reference substance as an intermediary that does not interact with the analyte but experiences the same environmental changes. This reference substance serves as a mediator to compensate for environmental variations by providing a stable reference signal for normalization, thereby maintaining measurement reliability while preserving detection sensitivity.
Solution Approach 2:
The patent changes the measurement parameter from absolute intensity to intensity ratio. By measuring the ratio of analyte signal to reference substance signal, the system eliminates the effect of environmental parameter changes (refractive index, excitation intensity, collection efficiency), thus maintaining both detection sensitivity and measurement reliability under varying conditions.
2Measurement precision
If conventional surface-enhanced Raman spectroscopy measures analyte concentration, then detection capability is improved, but quantitative accuracy deteriorates due to environmental interference
Solution Approach 1:
The patent converts the harmful effect of environmental variations into a beneficial normalization factor. By intentionally measuring a reference substance that experiences the same environmental changes, the system uses these variations as a basis for ratio calculation, thereby eliminating their harmful impact and achieving accurate quantitative measurement.
Solution Approach 2:
The reference substance acts as an intermediary that bridges the gap between environmental conditions and measurement accuracy. It provides a stable reference point that allows the system to distinguish between environmental effects and actual analyte concentration changes, thereby improving quantitative accuracy despite environmental interference.
3Reliability
If a single substance is used for detection, then device complexity is reduced, but measurement reliability deteriorates due to lack of environmental compensation
Solution Approach 1:
The patent segments the detection function into two independent components: the analyte-detecting substance and the reference substance. This segmentation allows each component to have a specialized function, with the reference substance dedicated to environmental compensation and the analyte substance dedicated to target detection, thereby improving reliability without significantly increasing overall complexity.
Solution Approach 2:
The reference substance serves multiple functions: it provides environmental compensation, enables normalization, and acts as an internal control. This multi-functionality allows a single additional substance to address multiple reliability issues simultaneously, improving detection reliability without requiring complex structural modifications.
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 accurate detection and quantification of analytes like glucose in biological bodies by isolating the effect of environmental changes, improving the precision and reliability of glucose concentration measurements.
Implementation Method 1
Surface-enhanced Raman scattering is a phenomenon in which Raman-scattered light from molecules that have adhered to the surface of a specially-designed sensor chip having a precious metal structure of nanometer size increases in intensity
Implementation Method 2
In Raman spectroscopy, a substance is irradiated with monochromatic light (excitation light) of a certain frequency so that scattered light occurs therefrom, and any scattered light that has a different frequency (hereinafter referred to as Raman-scattered light) from the frequency of the incident light is spectropically detected
Data Source
AI summary
An exemplary sensor chip includes a substrate, a metal pattern formed on a side of the substrate that is irradiated with excitation light, and a first substance and a second substance provided near the metal pattern. A first intensity Xa of the first surface-enhanced Raman-scattered light from the first substance and a second intensity Xb of the second surface-enhanced Raman-scattered light from the second substance are detected. An intensity ratio Xc, as obtained by dividing the second intensity Xb with the first intensity Xa, is calculated.