Thin Polymer Coating for Biosensor Sensitivity

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Solution Overview

Problem

Existing polymer layers on metallic bases in biosensors are too thick, leading to insufficient reduction in separative distance between metallic bases, which hampers detection sensitivity and allows nonspecific adsorption, thereby deteriorating the signal-to-noise ratio.

Innovation Solution

A polymer with a hydrophilic group bonded to a disulfide group is used to form a thin polymer layer on metallic bases, reducing the separative distance and inhibiting nonspecific adsorption through effective exposure of hydrophilic groups.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a polymer layer is formed on metallic base surface to inhibit nonspecific adsorption, then nonspecific adsorption is reduced, but the polymer layer thickness becomes too large, preventing sufficient reduction in separative distance between metallic bases

Engineering Contradiction:

Improvenonsspecific adsorptionVSAvoidpolymer layer thickness

Core Design Contradiction:

Object-affected harmful factorsVSLength of stationary object

Solution Approach 1:

The invention changes the chemical structure parameters of the polymer by introducing disulfide groups at side chain terminals that can form strong bonds with metallic surfaces. This allows the use of shorter polymer chains (reduced thickness) while maintaining effective nonspecific adsorption inhibition through the sulfur-metal interaction at the polymer-metallic base interface.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite structure where the polymer layer combines hydrophilic groups (for nonspecific adsorption inhibition) with disulfide groups (for strong metallic base bonding). This composite polymer structure enables thin layer formation while maintaining both adhesion strength and anti-nonspecific adsorption functionality.

Inventive Principle:

Principle #40Composite materials

2Object-affected harmful factors

If polymer chains are arranged in a brush shape perpendicular to metallic base surface, then nonspecific adsorption is inhibited, but the separative distance between metallic bases cannot be sufficiently reduced

Engineering Contradiction:

Improvenonspecific adsorptionVSAvoidseparative distance between metallic bases

Core Design Contradiction:

Object-affected harmful factorsVSLength of moving object

Solution Approach 1:

The invention changes the polymer chain conformation parameter from perpendicular (brush) arrangement to parallel arrangement relative to the metallic base surface. This is achieved through the disulfide group bonding mechanism that allows chains to lie flat against the surface, dramatically reducing the effective thickness and separative distance while maintaining nonspecific adsorption inhibition through exposed hydrophilic groups.

Inventive Principle:

Principle #35Parameter changes

3Measurement precision

If polymer layer thickness is reduced to decrease separative distance, then detection sensitivity is improved, but nonspecific adsorption inhibition becomes insufficient

Engineering Contradiction:

Improvedetection sensitivityVSAvoidnonspecific adsorption

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical composition parameter of the polymer by incorporating disulfide groups that form strong coordinate bonds with metallic surfaces. This allows ultra-thin polymer layers to maintain effective nonspecific adsorption inhibition through the sulfur-metal interaction at the interface, while the reduced thickness improves detection sensitivity by decreasing separative distance between metallic bases.

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

The proposed solution significantly enhances detection sensitivity by reducing the thickness of the polymer layer and improving the signal-to-noise ratio through effective inhibition of nonspecific adsorption.

Implementation Method 1

a hydrophilic group bonded with a disulfide group interposed

Methodology Applied

Scientific EffectChemisorption: Chemisorption

Implementation Method 2

a hydrophilic group that inhibits nonspecific adsorption to the surface of the metallic base

Methodology Applied

Scientific EffectHydrophilic interaction: Hydrophile

Implementation Method 3

surface plasmon resonance is induced in the metallic particles in the composite, and a near field in the vicinity of the surface of the metallic particle is formed. The near field increases the fluorescence intensity of the fluorescent substance.

Methodology Applied

Scientific EffectSurface plasmon resonance: Resonance

Data Source

PatentEP4535001A1Coated metallic base, production methdo therefor, composite including coated metallic base, and polymer for producing coated metallic base

Publication Date: 2025.04.09 PHC HLDG CORP

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AI summary

A coated metallic base comprising a metallic base being a metallic nanoparticle and/or a metallic film, a polymer layer covering a surface of the metallic base, and a first hydrophilic group that inhibits nonspecific adsorption to the surface of the metallic base, the first hydrophilic group being bonded to the surface of the metallic base, and the polymer layer containing a binding site with a sulfur atom interposed therein between the polymer layer and the surface of the metallic base.