Superparamagnetic Polymer Particles for Analyte Capture

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing magnetic particles are inadequate for automation processes due to small particle size and low saturation magnetization, leading to issues with surface area and magnetization, which affect their effectiveness in capturing analytes and causing matrix effects in LC/MS systems.

Innovation Solution

The development of magnetic particles with a particle size ranging from 1 to 60 micrometers and a saturation magnetization of at least 1 A m²/kg, comprising a polymer matrix and magnetic cores, preferably made of iron oxide nanoparticles, with a specific surface area of 50 to 2500 m²/g, and a superparamagnetic property.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If magnetic particles with small size (e.g., 100 nm or 400 nm) are used to increase specific surface area, then analyte capture efficiency is improved, but saturation magnetization becomes too low for automation processes

Engineering Contradiction:
Improvespecific surface areaVSAvoidsaturation magnetization
Core Design Contradiction:
Area of stationary objectVSQuantity of substance

Solution Approach 1:

The magnetic particle is segmented into two distinct functional components: a polymer matrix providing mechanical structure and magnetic cores providing magnetic properties. This segmentation allows the polymer matrix to be made larger (1-60 μm) for automation compatibility while the magnetic cores maintain high surface area for analyte capture.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention uses composite materials by combining polymer matrix with magnetic core materials (e.g., iron oxide nanoparticles). The polymer matrix provides bulk volume for adequate magnetization, while the magnetic cores concentrated on the surface provide high specific surface area for analyte binding.

Inventive Principle:
Principle #40Composite materials

2Quantity of substance

If particle size is increased to improve saturation magnetization for automation, then magnetic separation efficiency is improved, but specific surface area decreases reducing analyte capture capacity

Engineering Contradiction:
Improvesaturation magnetizationVSAvoidspecific surface area
Core Design Contradiction:
Quantity of substanceVSArea of stationary object

Solution Approach 1:

The magnetic cores are localized specifically at the surface or near-surface region of the polymer matrix particle. This local concentration of magnetic material maximizes the surface area available for analyte capture while the bulk polymer matrix provides the necessary volume for adequate saturation magnetization.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention transitions from considering only particle size as the determining factor to a two-dimensional approach: particle size (affecting magnetization) and surface area (affecting capture efficiency). By decoupling these through the composite structure, both requirements can be satisfied simultaneously.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Area of stationary object

If small magnetic particles are used to achieve high surface area, then analyte enrichment capability is improved, but magnetic separation speed becomes too slow for automation

Engineering Contradiction:
Improvespecific surface areaVSAvoidmagnetic separation speed
Core Design Contradiction:
Area of stationary objectVSSpeed

Solution Approach 1:

The particle is segmented into a bulk polymer matrix for fast magnetic response and surface-localized magnetic cores for high surface area. This allows the particle to respond quickly to magnetic fields (due to adequate magnetization from the matrix volume) while maintaining high analyte capture capacity (due to high surface area from the concentrated cores).

Inventive Principle:
Principle #1Segmentation

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 solution provides magnetic particles suitable for automation processes with enhanced capture efficiency and reduced matrix effects, enabling effective analyte determination in fluid samples.

Implementation Method 1

superparamagnetic materials get more attention as they only show magnetization when an external magnetic field is applied. In the absence of an external magnetic field, magnetization appears to be zero

Methodology Applied
Scientific EffectSuperparamagnetism: Superparamagnetism

Implementation Method 2

High specific surface areas on the magnetic particles are required to enrich analytes from human samples. To increase the surface area... materials with micropores (pores

Methodology Applied
Scientific EffectPorosity: Porosity

Data Source

PatentEP4707808A2Superparamagnetic and highly porous polymer particles for diagnostic applications
Publication Date: 2026.03.11 ROCHE DIAGNOSTICS GMBH
  • EP4707808A2 patent drawingFigure 1
  • EP4707808A2 patent drawingFigure 2
  • EP4707808A2 patent drawingFigure 3

AI summary

The present invention relates to a method of preparing magnetic particles, wherein each particle comprises a polymer matrix (P) and at least one magnetic core (M), wherein the polymer matrix comprises at least one crosslinked polymer and wherein the magnetic particle has a particle size in the range of from 1 to 60 micrometers, and to particles obtainable or obtained by said method. Moreover, the present invention is concerned with the use of these magnetic particles for qualitative and/or quantitative determination of at least one analyte in a fluid. Further, the present invention relates to a method for determining at least one analyte in a fluid sample comprising the contacting of a magnetic particle obtained by the method of the present invention with a fluid sample comprising or suspected to comprise the at least one analyte.