Biosensor Ligand-Layer Quality Control with Integrated Reference Binding

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Solution Overview

Problem

Existing quality control methods for biosensors are labor-intensive, expensive, and prone to errors, with potential degradation of DNA-ligands over time, and cannot provide quantitative ligand density measurements, especially when using reference ligands or sacrificing sensors for QC.

Innovation Solution

Integrate a quality control target binding section within the same molecule as the analyte binding section, allowing for real-time QC during assays by using a known concentration of a quality control target molecule to generate a pre-determined binding signal, ensuring each biosensor meets specifications without loss or error.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional quality control methods (XPS, WCA, ellipsometry, fluorescence microscopy) are used to test ligand density, then measurement capability is provided, but the process is labor-intensive, expensive, and can only be performed as sampling rather than automation

Engineering Contradiction:
Improveligand density measurementVSAvoidQC process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The biosensor performs self-quality control by incorporating a reference ligand that automatically reports on its own immobilization quality during the assay. The reference ligand binds the reference target and generates a signal that indicates whether the ligand layer meets specifications, eliminating the need for external QC equipment and manual sampling.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The reference ligand serves multiple functions: it acts as a quality control indicator, a calibration standard, and a functional component of the biosensor. By integrating QC capability into the sensor itself, the system achieves both measurement and self-diagnosis without requiring separate QC instruments.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If sensors are sacrificed for quality control using reference ligands, then QC can be performed, but the sensor is lost and cannot be used for analyte detection

Engineering Contradiction:
ImproveQC reliabilityVSAvoidsensor loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The reference ligand and analyte detection ligand are combined into a single biosensor device, allowing both QC function and analyte detection function to coexist. The reference ligand is positioned to bind the reference target while the analyte ligand binds the analyte, enabling simultaneous QC monitoring and diagnostic testing without sacrificing either function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reference ligand is immobilized on the sensor surface during manufacturing as a preliminary quality control measure. This allows the sensor to be pre-validated for ligand layer quality before being used for analyte detection, ensuring reliability without requiring post-production sacrifice of sensors.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If reference ligand is mixed with analyte probe during immobilization, then both can be present on sensor, but the immobilization process becomes more complicated and errors may occur

Engineering Contradiction:
Improveprobe functionalityVSAvoidimmobilization process simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The immobilization process is segmented into separate steps: first the reference ligand is immobilized on the sensor surface, then the analyte probe is immobilized in a subsequent step. This segmentation prevents interaction between different probes during immobilization, simplifies the manufacturing process, and ensures proper orientation and density of each ligand type without requiring complex mixed-immobilization protocols.

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

Enables fast, reliable, and quantitative quality control of biosensor ligand layers, ensuring each sensor is tested and within specifications, reducing complexity and costs while maintaining accuracy.

Implementation Method 1

contacting the biosensor with a determined concentration of a quality control target and determining the ligand density based on the binding signal generated by the quality control target

Methodology Applied
Scientific EffectBinding:

Data Source

PatentEP4644900A1Quality control of biosensors
Publication Date: 2025.11.05 QU-IP BV
  • EP4644900A1 patent drawingFigure 1~2
  • EP4644900A1 patent drawingFigure 3~4
  • EP4644900A1 patent drawingFigure 5~6

AI summary

The present invention relates to a method for quality control of the ligand layer of a biosensor, comprising providing a biosensor coated with a ligand comprising a quality control target binding section and an analyte binding section and contacting the biosensor with a determined concentration of a quality control target molecule and determining the ligand density based on the binding signal generated by the quality control target molecule. The ligand is suitably bound to the sensor surface by the quality control target binding section of the ligand or by the analyte binding section of the ligand. The ligand can be a nucleic acid molecule, specifically a DNA probe. The ligand can also be a protein or an antibody. The method may comprise a further step of contacting the biosensor with the analyte to be detected.