Polymer Monolayer Immunosensor for Reducing Nonspecific Adsorption

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Solution Overview

Problem

Current immunosensors face challenges in minimizing nonspecific adsorption and achieving low detection limits, particularly in detecting specific analytes in complex samples, which limits their effectiveness in applications such as food, biomedical, and environmental monitoring.

Innovation Solution

The development of an immunosensor device with a nanostructured interface created by sequential deposition of redox or non-redox polymer monolayers and submonolayers of affinity elements, allowing for electrochemical, optical, and piezoelectric transduction, which minimizes nonspecific adsorption and enables direct detection of analytes in a single step without additional immunoreactive agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional immunosensor construction methods are used, then the device can detect analytes, but nonspecific adsorption increases and detection limits worsen

Engineering Contradiction:
Improvedetection limitVSAvoidnonspecific adsorption
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The sensor surface is segmented into multiple functional layers: a polymer monolayer base structure, followed by submonolayers of affinity elements (antibodies), and finally the analyte layer. This segmentation allows each layer to perform its specific function - the polymer layer provides structural integrity and reduces nonspecific adsorption, while the affinity element layers enable specific analyte binding, thereby improving detection precision without increasing nonspecific adsorption.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The immunosensor employs composite material structure combining polymer monolayers (redox or non-redox polymers) with biological affinity elements (antibodies). This composite approach integrates the advantages of both materials: polymers provide stable, controllable surfaces with reduced nonspecific binding, while antibodies provide high-specificity recognition. The combination achieves low detection limits while minimizing nonspecific adsorption interference.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If multiple immunoreactive agents are used for detection, then detection accuracy improves, but device complexity and analysis time increase

Engineering Contradiction:
Improvedetection accuracyVSAvoidnumber of immunoreactive agents
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The polymer monolayer platform serves as a universal base structure that can support various types of affinity elements (different antibodies) and work with multiple transduction methods (electrochemical, optical, piezoelectric). This multi-functionality allows the same basic sensor architecture to detect different analytes without requiring complex reconfiguration, reducing device complexity while maintaining detection accuracy through the universal platform design.

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

Solution Approach 2:

The polymer monolayer acts as an intermediary layer between the sensor surface and the affinity elements. This intermediary structure simplifies the overall system by providing a standardized interface that facilitates the attachment of various antibodies and enables different transduction mechanisms, thereby reducing the complexity associated with using multiple immunoreactive agents while maintaining detection precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If sequential deposition of multiple layers is performed, then nonsspecific adsorption is minimized, but manufacturing time increases

Engineering Contradiction:
Improvenonspecific adsorptionVSAvoidmanufacturing time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The polymer monolayer is deposited in advance as a preparatory step before attaching the affinity elements. This preliminary action creates a optimized surface structure that inherently minimizes nonspecific adsorption, reducing the need for additional blocking layers or complex post-processing steps. By performing this key function early in the manufacturing process, the overall time is reduced while maintaining low nonsspecific adsorption levels.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sequential deposition process is designed as a continuous manufacturing workflow where each layer is deposited and immediately prepared for the next layer without interruption. The polymer monolayer formation, affinity element attachment, and final sensor activation occur in continuous sequence, minimizing idle time between steps. This continuous action approach reduces total manufacturing time while maintaining the beneficial effect of minimized nonspecific adsorption through the complete multi-layer structure.

Inventive Principle:
Principle #20Continuity of useful action

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 results in a fast, portable, and cost-effective immunosensor capable of detecting and quantifying analytes with reduced nonspecific adsorption, enabling real-time analysis and low detection limits, suitable for various applications including environmental and clinical diagnostics.

Implementation Method 1

sequential deposition of self-assembled monolayers of polymers and affinity elements

Methodology Applied
Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 2

monolayers of polymers (redox or non-redox) covering the sensor surface

Methodology Applied
Scientific EffectRedox reactions: Redox Reactions

Data Source

PatentEP2960650B1Analytical immunosensor device and method for constructing same
Publication Date: 2019.10.23 UNIV DE ALCALA
  • EP2960650B1 patent drawingFigure 1~2a
  • EP2960650B1 patent drawingFigure 2b~2c
  • EP2960650B1 patent drawingFigure 3~4

AI summary

The invention relates to an analytical immunosensor device and to a method for the constructing same, based on the sequential deposition of self-assembled monolayers of polymers and affinity elements, applicable for the detection and quantification of any target antigen or analyte in a liquid sample, and allowing the implementation of the "quasi-reagentless" or "reagentless" displacement assay, the minimisation of the non-specific adsorption and, as a result, the reduction of the detection limit. Said device is designed on the basis of a sensor surface covered with polymer monolayers (redox or non-redox) on which are deposited sub-monolayers of affinity elements, in order to subsequently carry out the affinity reaction with an antigen, pseudo-antigen or a hapten marked with a protein, preferably an enzyme (redox or non-redox) or a nanoparticle, allowing said method for constructing the device to develop "a la carte" immunosensors, with an electrochemical, optical and/or piezoelectric transduction of the signal.