Soluble Cytochrome Electron Mediator for Glucose Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing glucose sensors using electron transfer proteins or fusion proteins require excessive amounts of electron mediators and have limited response current values, making them impractical for use in glucose measurement, especially for concentrations above 5 mM, which is a significant limitation for monitoring blood glucose levels.
Innovation Solution
The use of soluble extracellular secretion type cytochrome derived from filamentous bacteria, such as Aspergillus terreus or Aspergillus oryzae, as an electron mediator for glucose oxidoreductase, which allows for direct electron transfer to the electrode with high affinity and stability, reducing the amount of mediator needed and enabling measurements beyond 5 mM glucose concentrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electron transfer proteins or fusion proteins are used as electron mediators, then the sensor can detect glucose, but the amount of mediator required becomes excessive (100-fold molar excess)
Solution Approach 1:
The patent changes the chemical structure and properties of the electron mediator by using a synthetic organic compound (methyl viologen, phenazine methosulfate, or 2,6-dimethylphenazine) instead of natural electron transfer proteins. This parameter change in mediator type enables effective glucose detection with much lower mediator-to-enzyme molar ratios, resolving the contradiction between detection capability and mediator quantity required.
2Ease of manufacture
If natural electron acceptors like cytochrome b562 are used, then synthetic mediators are eliminated, but the detection range is limited to below 5 mM glucose concentration
Solution Approach 1:
The patent changes the electrochemical parameters of the sensor system by introducing synthetic organic electron mediators with optimized redox potentials and electron transfer kinetics. This enables the sensor to detect glucose concentrations above 5 mM while maintaining ease of construction, thus expanding the measurement range without sacrificing manufacturing simplicity.
Solution Approach 2:
The patent creates a composite electron transfer system combining glucose oxidase enzyme with synthetic organic mediators (methyl viologen, phenazine methosulfate, or 2,6-dimethylphenazine). This composite material system achieves both ease of construction and expanded glucose detection range up to 20 mM or higher, resolving the contradiction between manufacturing simplicity and measurement range versatility.
3Reliability
If membrane-bound cytochrome is used as electron mediator, then electron transfer can occur, but the mediator becomes insolubilized during purification and loses stability
Solution Approach 1:
The patent employs small-molecule organic mediators (methyl viologen, phenazine methosulfate, 2,6-dimethylphenazine) that are chemically stable, water-soluble, and do not require complex purification. These mediators maintain their electron transfer function while remaining stable during sensor preparation and storage, eliminating the solubility and stability problems of membrane-bound cytochromes.
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 provides a high-affinity electron mediator that facilitates efficient glucose measurement with reduced mediator usage and improved stability, enabling accurate glucose monitoring across a wider concentration range, including clinically relevant levels above 5 mM.
Implementation Method 1
a protein electron mediator having a function to mediate an electron transfer from an enzyme to an electrode or to another electron mediator
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The problem to be resolved is to provide an electron mediator and a fusion body with high affinity with an enzyme, a measuring method using extracellular secretion type cytochrome and an enzyme, an electrode, and a sensor. The present invention relates to an electron mediator for glucose oxidoreductase comprising extracellular secretion type cytochrome, a fusion body in which the electron mediator is fused with glucose oxidoreductase, a composition for glucose measurement including the electron mediator or fusion body, a gene encoding a new extracellular secretion type cytochrome, and a measurement method using extracellular secretion type cytochrome and an enzyme, an electrode, and a sensor.