High Contrast Grating Optical Sensor for Surface Plasmon Resonance
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Solution Overview
Problem
Current biosensors face limitations in sensitivity, reliability, and speed due to environmental denaturation of recognition elements and inherent detection limitations in transducer platforms, particularly in detecting unlabeled analytes and multiple infectious agents simultaneously.
Innovation Solution
A surface plasmon resonance-based optical sensor platform with a high contrast grating, a thin metal film, and a low index spacer, which uses surface plasmon waves to detect refractive index changes induced by target interactions, enabling label-free detection with improved sensitivity and tolerance for environmental variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If traditional optical coupling methods are used with surface plasmon polariton platforms, then the device structure is simpler, but the optical coupling efficiency is low and the quality factor of optical resonance is reduced
Solution Approach 1:
A high contrast grating structure is introduced as an intermediary element between the optical beam and the surface plasmon polariton platform. This grating acts as a mediator that facilitates efficient coupling by matching the momentum of incident light with the surface plasmon modes, thereby significantly improving optical coupling efficiency while maintaining a manageable device structure.
Solution Approach 2:
The grating structure modifies the optical parameters (wavevector, phase matching conditions) to enable efficient coupling. By changing the spatial periodicity and geometric parameters of the grating, the system achieves optimal momentum matching between free-space photons and surface plasmon polaritons, enhancing coupling efficiency without excessive structural complexity.
2Measurement precision
If conventional biosensing methods are used, then the equipment and procedures are simpler, but the detection sensitivity and speed are reduced
Solution Approach 1:
The patent replaces conventional mechanical or chemical assay methods with an optical sensing mechanism based on surface plasmon resonance. This substitution enables label-free detection with high sensitivity by measuring refractive index changes at the sensor surface, eliminating the need for complex labeling procedures and manual preparation steps while achieving rapid detection.
Solution Approach 2:
The optical sensing platform provides a universal detection mechanism that can identify multiple infectious agents simultaneously through label-free optical measurement. The system's ability to detect various biomolecules (viruses, bacteria) using the same physical principle enhances measurement precision while maintaining operational simplicity compared to agent-specific assays.
3Measurement precision
If high sensitivity detection is achieved through traditional methods, then the detection limit is improved, but the tolerance to environmental variations and denaturation of recognition elements worsens
Solution Approach 1:
The patent converts the typically harmful effect of environmental denaturation on recognition elements into a beneficial detection mechanism. By using label-free optical sensing that detects refractive index changes directly, the system eliminates the need for fragile biological recognition elements that are susceptible to environmental denaturation, thereby achieving both high sensitivity and reliability simultaneously.
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 platform achieves cost-effective, high-sensitivity detection of multiple analytes with quick response times, reducing the need for sample purification and labeled reagents, and facilitating efficient optical coupling for enhanced sensitivity and reliability.
Implementation Method 1
the metal layer has an excitation surface along an interface between the carrier material and the metal layer, along which surface plasmon polaritons travel when the excitation surface is excited by a light source
Implementation Method 2
the high contrast grating provides phase matching between the light source and the surface plasmon polaritons to couple photons from the light source to the surface plasmon polaritons for excitation
Implementation Method 3
A surface plasmon resonance-based optical sensor platform with a high contrast grating, a thin metal film, and a low index spacer, which uses surface plasmon waves to detect refractive index changes induced by target interactions
Data Source
AI summary
An optical sensing platform with an array of sensors, a laser or broadband light source and an optical detector that utilizes surface plasmon resonance based transduction and optical detection is provided. The sensor structure of the platform has a low index support layer, a high contrast grating, a low index spacer and a thin metal film with a target recognition element. The surface plasmon resonance based sensor uses surface plasmon waves to detect changes on the surface of the sensor when a target interacts with the target recognition element. The binding of the target with a recognition element receptor will induce changes in the refractive index of the metal layer, which changes the resonance wavelength of the plasmon wave on the sensor surface, which is used to measure or observe the reaction.