Osmium Complex Mediator for Stable Glucose Biosensor

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional electrochemical blood glucose sensors face challenges with measurement accuracy due to interference from substances like uric acid and gentisic acid, and have stability issues with temperature and humidity, making it difficult to accurately detect glucose at low concentrations and requiring frequent calibration, especially in continuous glucose monitoring systems where user convenience and minimization of invasiveness are critical.

Innovation Solution

A transition metal complex with a bidentate ligand comprising pyrazole, triazole, tetrazole, oxadiazole, or thiadiazole is used as an electron transfer mediator, integrated into an oxidation-reduction polymer, which is applied in an electrochemical biosensor that can be inserted into the body, enhancing electron transfer efficiency and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If potassium ferricyanide is used as an electron transfer mediator, then reactivity and cost-effectiveness are improved, but stability against temperature and humidity deteriorates, and measurement errors increase due to interfering substances

Engineering Contradiction:

ImprovestabilityVSAvoidmeasurement accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The patent changes the chemical parameters of the electron transfer mediator by replacing potassium ferricyanide with osmium complexes having different oxidation-reduction potentials and stability characteristics. This parameter change resolves the contradiction by selecting osmium complexes that maintain stability across varying temperature and humidity conditions while avoiding interference from blood substances like uric acid and gentisic acid.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent employs organic compounds such as quinone derivatives and osmium complexes that, while potentially more expensive initially, provide long-term stability and reusability without degradation from humidity and temperature variations. This effectively replaces the 'cheap but short-living' potassium ferricyanide with more durable mediators, resolving the stability-accuracy contradiction.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Reliability

If the distance from the active center of the enzyme is increased, then enzyme stability is improved, but electron transfer efficiency deteriorates

Engineering Contradiction:

Improveenzyme stabilityVSAvoidelectron transfer speed

Core Design Contradiction:

ReliabilityVSSpeed

Solution Approach 1:

The patent introduces osmium complexes as intermediary electron transfer mediators between the enzyme active center and the electrode. These osmium complexes act as a bridging substance that can accept electrons from the enzyme at a distance and efficiently transfer them to the electrode, thus resolving the contradiction between maintaining enzyme stability at a distance and ensuring rapid electron transfer.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite sensing system combining the enzyme (GDH), osmium complex mediator, and electrode in a integrated structure. This composite material approach allows optimal positioning of components where the enzyme remains stable at a appropriate distance while the osmium complex ensures efficient electron transfer, simultaneously achieving both stability and speed requirements.

Inventive Principle:

Principle #40Composite materials

3Device complexity

If conventional optical methods are used for glucose detection, then simplicity is maintained, but accuracy deteriorates due to oxygen interference and requirement for sample retreatment

Engineering Contradiction:

Improvedetection method simplicityVSAvoidglucose detection accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces the optical detection method with an electrochemical detection system using osmium complexes as electron transfer mediators. This substitution eliminates the interference from oxygen and the need for sample retreatment while maintaining a relatively simple sensor structure, thus resolving the contradiction between simplicity and accuracy in glucose detection.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 enables rapid, accurate, and economical glucose detection with improved stability and reduced interference, addressing the limitations of conventional sensors by enhancing electron transfer speed and maintaining performance across varying conditions.

Implementation Method 1

an oxidation-reduction mediator, that is, an electron transfer mediator is necessarily required

Methodology Applied

Scientific EffectOxidation-reduction reaction: Redox Reactions

Data Source

PatentUS20240376513A1Electrochemical biosensor, or sensing membrane for electrochemical biosensor containing transition metal complex or oxidation-reduction polymer

Publication Date: 2024.11.14 I SENS INC

AI summary

The present invention relates to: a transition metal complex having a bidentate ligand which includes pyrazole, triazole, tetrazole, oxadiazole, thiadiazole, or the like, wherein the transition metal complex can be used as an electron transfer mediator in a continuous blood glucose monitor and the like for measuring blood glucose concentration; and an oxidation-reduction polymer comprising same. The transition metal complex and the oxidation-reduction polymer can quickly and smoothly exchange electrons between an enzyme and an electrode, and thus can be effectively used in a continuous blood glucose biosensor.