SPR Sensor Artefact Correction via Reference Beam

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Solution Overview

Problem

Current SPR sensing systems are prone to measurement errors due to external factors like temperature variations, light source instabilities, and mechanical shocks, which cause artefacts that are not detected or corrected.

Innovation Solution

The method involves monitoring both the SPR condition and the intensity of a reference light that does not excite SPR, allowing for the detection and correction of artefacts by using a reference light beam with a narrow spectral width, far from the SPR peak, to filter and correct the test light beam measurements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a reference light beam is introduced to monitor artefacts, then measurement reliability is improved, but device complexity increases

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical measurement system is segmented into two independent channels: a test light beam path for SPR measurement and a reference light beam path for artefact monitoring. This segmentation allows the reference channel to independently monitor environmental disturbances without interfering with the test measurement, thereby improving reliability while maintaining manageable system complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reference light beam acts as an intermediary that indirectly monitors environmental artefacts (temperature, mechanical shocks) affecting the SPR measurement. By measuring the reference beam's intensity variations caused by these artefacts, the system can compensate for their effects on the test measurement, improving reliability without requiring direct monitoring of each environmental parameter

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If artefact correction is implemented, then measurement precision is improved, but processing complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system implements feedback by using the reference light beam intensity measurements to correct the test light beam measurements. The reference channel provides real-time information about environmental artefacts, which is fed back to compensate for their effects on the SPR measurement, thereby improving precision through a relatively simple correction algorithm

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The correction method involves changing the interpretation of measurement parameters by comparing the test beam intensity with the reference beam intensity. By analyzing the ratio or difference between these two parameters, the system extracts artefact-free SPR signal, improving measurement precision through straightforward parameter transformation rather than complex processing

Inventive Principle:
Principle #35Parameter changes

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 reliability of SPR sensing by accurately distinguishing and correcting for artefacts, thereby improving the accuracy of refractive index measurements.

Implementation Method 1

a test light beam is directed towards a sensor surface so as to excite surface plasmon resonance (SPR) thereon

Methodology Applied
Scientific EffectSurface plasmon resonance: Resonance

Implementation Method 2

In the resonance condition, the incident light is absorbed by the metal-dielectric interface so as to couple with the surface-bond electromagnetic wave

Methodology Applied
Scientific EffectLight absorption: Absorption (EM radiation)

Implementation Method 3

the sensor surface is simultaneously illuminated by a reference light beam under conditions selected so as not to excite surface plasmon resonance at said sensor surface

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2443438B1A surface plasmon resonance sensing method and sensing system
Publication Date: 2015.05.06 EUROPEAN COMMUNITY (EC)
  • EP2443438B1 patent drawingFigure 1
  • EP2443438B1 patent drawingFigure 2~3
  • EP2443438B1 patent drawingFigure 4~5

AI summary

A SPR sensing method comprising the steps of: providing a SPR sensor comprising a SPR supporting sensor surface and contacting a sample to be analysed with the sensor surface. At least one resonance condition at said SPR supporting sensor surface is monitored by illuminating the sensor surface with an SPR exciting test light beam and sensing the reflected or transmitted test light beam. Additionally, the sensor surface is illuminated with a reference light beam under conditions selected so as not to excite SPR at said sensor surface and sensing the intensity of the reflected or transmitted reference light beam. At least one property of the reflected or transmitted test light beam is determined taking into account the sensed intensity of the reflected or transmitted reference light beam.