3D Hydrogel-Graphene Biosensor Biofouling Resistance

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Solution Overview

Problem

Graphene-based nano-biosensors face stability and sensitivity issues due to biofouling from non-target biological macromolecules and impurities in biological samples, leading to sensor failure.

Innovation Solution

A three-dimensional hydrogel-graphene-based biosensor is developed, featuring a hydrogel material with a three-dimensional network structure formed by polymerizing acrylamide monomers and modified probe molecules, which creates a filter-like effect to block impurities and enhance sensitivity by adjusting the electrostatic induction effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a surface-affinity sensor is used where the graphene surface is always exposed to the solution, then the sensor can detect target molecules through electrostatic induction, but non-target biological macromolecules and impurities form biofouling on the graphene surface, affecting stability and sensitivity

Engineering Contradiction:

Improvedetection sensitivityVSAvoidsensor stability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by creating a hydrogel layer with specific local properties (porosity, charge density, hydrophilicity) at the graphene-solution interface. This hydrogel layer has a different structure and function from the bulk solution, providing a localized filtering and protective environment that allows target molecule detection while blocking biofouling substances.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The hydrogel layer serves as an intermediary between the graphene surface and the biological solution. It mediates the interaction by allowing small target molecules to pass through while blocking larger biofouling substances, thus protecting the graphene surface without preventing target detection.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a protective layer is added to prevent biofouling, then sensor stability improves, but the sensitivity and response speed may decrease due to additional diffusion barriers

Engineering Contradiction:

Improvesensor stabilityVSAvoidresponse speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent uses a porous hydrogel layer as the protective structure. The porous nature allows small target molecules to diffuse through quickly while blocking larger biofouling substances. The pore size and distribution are optimized to maintain fast response speed while providing effective protection against biofouling.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The sensor combines graphene with hydrogel materials to create a composite structure. The graphene provides high sensitivity and electrical conductivity, while the hydrogel provides protection against biofouling. The composite structure achieves both stability and sensitivity without significant compromise in response speed.

Inventive Principle:

Principle #40Composite materials

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 biosensor achieves improved stability and sensitivity, allowing for accurate detection of target molecules with a wider range and reduced biofouling, as demonstrated by effective detection of cardiac troponin I across various concentrations and conditions.

Implementation Method 1

the hydrogel material has a three-dimensional network structure... creates a filter-like effect to block impurities

Methodology Applied

Scientific EffectPhysical filtration: Filter (physical)

Implementation Method 2

weakly-charged marker molecules in a solution to be tested captured by the probe molecule may affect the number of mobile carriers per unit cross-sectional area inside the graphene under the action of 'electrostatic induction'

Methodology Applied

Scientific EffectElectrostatic induction: Electrostatic Induction

Implementation Method 3

the hydrogel material is obtained by polymerization of raw materials including an acrylamide monomer and a modified probe molecule

Methodology Applied

Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS11619602B2Three-dimensional hydrogel-graphene-based biosensor and preparation method thereof

Publication Date: 2023.04.04 HARBIN INST OF TECH

AI summary

The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor and a preparation method thereof, belonging to the technical field of biosensors. The present disclosure provides a three-dimensional hydrogel-graphene-based biosensor, including a substrate, an electrode layer, a graphene film, and a three-dimensional hydrogel material layer that are stacked in sequence; where the three-dimensional hydrogel material layer is formed of a hydrogel material having a three-dimensional network structure; the hydrogel material is obtained by polymerization of raw materials including an acrylamide monomer and a modified probe molecule; and the modified probe molecule is a probe molecule modified with an acrylamide group. The three-dimensional hydrogel-graphene-based biosensor has a desirable stability and a high sensitivity.