Sensor Chip Blocking Strategy for SPR Fluorescence Noise

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Solution Overview

Problem

Existing sensor chips for surface plasmon-field enhanced fluorescence spectroscopy face issues with non-specific adsorption of contaminants from biological samples and reduction in autofluorescence blocking effectiveness over time due to partial detachment of the metal thin film from the dielectric member, leading to increased noise signals.

Innovation Solution

The solution involves restricting the blocking treatment to only the necessary areas where capturing substances are immobilized, using blocking agents suitable for each substance, and minimizing the exposure of the metal thin film to moisture to prevent detachment, thus maintaining the effectiveness of autofluorescence blocking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If blocking treatment is performed over the entirety of the wetted surface between measurement sample and metal thin film, then non-specific adsorption of contaminants is inhibited, but metal thin film partially detaches from dielectric member over time reducing autofluorescence blocking effectiveness

Engineering Contradiction:
Improvenon-specific adsorption of contaminantsVSAvoidautofluorescence blocking effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent applies local quality by performing blocking treatment only in the sensor section where capturing substances are immobilized, rather than over the entire wetted surface. This localized approach prevents non-specific adsorption at the sensor section while minimizing blocking agent exposure to the metal thin film, thereby preventing detachment and maintaining autofluorescence blocking effectiveness in non-sensor regions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the wetted surface into sensor section and non-sensor regions, applying blocking treatment only to the sensor section. This segmentation allows selective blocking where needed while preserving metal thin film integrity in other areas, resolving the contradiction between preventing non-specific adsorption and maintaining autofluorescence blocking.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If blocking agent solution is introduced to entire flow channel, then non-specific adsorption is prevented, but moisture from blocking agent causes metal thin film swelling and detachment

Engineering Contradiction:
Improvenon-specific adsorption of contaminantsVSAvoidmetal thin film adhesion to dielectric member
Core Design Contradiction:
Object-affected harmful factorsVSStability of the object's composition

Solution Approach 1:

The patent applies blocking agent solution only to the sensor section rather than the entire flow channel. This localized application prevents non-specific adsorption at the sensor section while minimizing moisture exposure to the metal thin film in non-sensor regions, preventing swelling and detachment.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by applying blocking treatment only where capturing substances are immobilized (sensor section) rather than excessively treating the entire wetted surface. This partial application achieves the necessary blocking effect while avoiding harmful moisture exposure to the metal thin film.

Inventive Principle:
Principle #16Partial or excessive action

3Object-affected harmful factors

If blocking treatment covers entire metal thin film surface, then non-specific adsorption is inhibited, but autofluorescence noise increases due to metal thin film detachment

Engineering Contradiction:
Improvenon-specific adsorption of contaminantsVSAvoidautofluorescence noise from dielectric member
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent performs blocking treatment only in the sensor section where capturing substances are immobilized, rather than covering the entire metal thin film surface. This localized approach prevents non-specific adsorption at the sensor section while preserving the metal thin film's autofluorescence blocking capability in non-sensor regions, thereby reducing autofluorescence noise.

Inventive Principle:
Principle #3Local quality

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 effectively inhibits non-specific adsorption of contaminants and maintains the blocking of autofluorescence, reducing noise and ensuring high-sensitivity measurements over time without reducing the autofluorescence blocking effect.

Implementation Method 1

under a condition where attenuated total reflection (ATR) of an excitation light such as a laser beam irradiated from a light source occurs at the surface of a metal thin film, the surface of the metal thin film is allowed to generate surface plasmon (compression wave)

Methodology Applied
Scientific EffectSurface plasmon:

Implementation Method 2

under a condition where attenuated total reflection (ATR) of an excitation light such as a laser beam irradiated from a light source occurs at the surface of a metal thin film

Methodology Applied
Scientific EffectAttenuated total reflection:

Implementation Method 3

by utilizing this electric field-enhancing effect to efficiently excite a fluorescent substance bound with a compound to be measured that is captured in the vicinity of the surface of the metal thin film and observing the thus generated fluorescence

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentEP3112870B1Sensor chip for surface plasmon-field enhanced fluorescence spectroscopy comprising different blocking agents
Publication Date: 2020.05.27 KONICA MINOLTA INC
  • EP3112870B1 patent drawingFigure 1
  • EP3112870B1 patent drawingFigure 2a
  • EP3112870B1 patent drawingFigure 2b

AI summary

An object of the present invention is to provide a sensor chip in which non-specific adsorption of contaminants originating from a measurement sample (biological sample) to a sensor section is effectively inhibited and the effect of blocking autofluorescence emitted by a dielectric member is not reduced with time. The sensor chip of the present invention is a sensor chip for surface plasmon-field enhanced spectroscopy that includes: a dielectric member; a metal thin film formed on a main surface of the dielectric member; and a region on a part of the metal thin film, where a capturing substance that specifically captures a substance to be measured is immobilized, wherein a blocking treatment with a blocking agent is performed in a region that includes the region where the capturing substance is immobilized and the blocking treatment is not performed over the entirety of a wetted surface between a measurement sample and the metal thin film.