Multimode Plasmon Waveguide Resonance Sensor for Bulk and Surface Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surface plasmon resonance (SPR) spectroscopy cannot distinguish between variations in multiple parameters within the penetration depth, leading to cross-sensitivity issues in biosensing applications.
Innovation Solution
A plasmon waveguide resonance sensor is developed, which operates in multiple resonance modes (transverse magnetic and transverse electric) at a single wavelength, utilizing a dielectric or metallic grating coupled with a surface plasmon resonance sensor to differentiate between surface and bulk sensing, enabling multimode spectroscopy without the need for multiple lasers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional SPR spectroscopy is used, then high sensitivity to refractive index variations is achieved, but the ability to distinguish between variations in multiple parameters (adlayer thickness, adlayer refractive index, bulk refractive index) is lost
Solution Approach 1:
The invention segments the sensing capability by introducing multiple resonance modes (surface resonance mode and bulk resonance mode) that probe different depths within the penetration region. The surface resonance mode is localized near the metal-dielectric interface and is sensitive primarily to adlayer properties, while the bulk resonance mode extends deeper into the fluid and is sensitive to bulk refractive index variations. This segmentation allows independent measurement of adlayer thickness, adlayer refractive index, and bulk refractive index, resolving the cross-sensitivity problem of conventional SPR spectroscopy.
2Measurement precision
If multiple lasers of different wavelengths are used to achieve multimode spectroscopy, then parameter differentiation is improved, but device complexity increases
Solution Approach 1:
The invention makes a single laser source perform multiple functions by utilizing both surface resonance mode and bulk resonance mode at the same wavelength. The sensor structure is designed to support multiple resonance modes simultaneously, allowing one laser to excite both modes and provide differentiation between adlayer and bulk parameters. This eliminates the need for multiple laser sources while maintaining the parameter differentiation capability, significantly reducing device complexity.
3Adaptability or versatility
If a dielectric layer is added to enable waveguide resonance modes, then multimode spectroscopy capability is achieved, but manufacturing complexity increases
Solution Approach 1:
The invention achieves multimode spectroscopy capability by carefully controlling the thickness parameter of the dielectric layer. By optimizing the dielectric layer thickness to be between 50-200 nm, the sensor structure supports both surface resonance mode and bulk resonance mode at a single wavelength. This parameter optimization allows the use of standard thin film deposition techniques without requiring complex multi-layer structures or additional manufacturing steps, maintaining ease of manufacture while enabling advanced functionality.
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
The sensor achieves improved sensitivity and resolution, allowing for precise measurement of adlayer and bulk refractive index variations, with potential applications in refractive index sensing, thin film investigation, and nanoparticle characterization, while being less sensitive to temperature fluctuations.
Implementation Method 1
Surface plasmon resonance (SPR) spectroscopy is a well-established optical technique commonly used for this purpose. Surface plasmon resonance (SPR) has gained interest as an efficient mechanism for biosensing.
Implementation Method 2
SPR biosensors are sensitive to the refractive index variations occurring within the penetration depth of their evanescent fields.
Implementation Method 3
a dielectric grating coupled to the surface plasmon resonance sensor for diffracting light
Implementation Method 4
SPR biosensors are sensitive to the refractive index variations occurring within the penetration depth of their evanescent fields
Data Source
AI summary
Apparatuses and methods for spectroscopy using multiple resonance modes are provided. Multiple resonance modes may be used for bulk sensing and/or surface sensing applications. A plasmon waveguide resonance sensor is provided for multimode spectroscopy. The sensor includes a dielectric layer; and a metallic layer coupled to the dielectric layer. The sensor is configured to provide: a first resonance mode for bulk sensing, in response to light of a given wavelength; and a second resonance mode for surface sensing, in response to light of the given wavelength. The first and second resonance modes have different polarizations. Surface plasmon resonance assemblies are provided having a grating coupled to a surface plasmon resonance sensor, the grating being a dielectric grating or a metallic grating. The grating, in response to light, provides various resonance modes having at least two different polarizations for bulk and surface sensing.