Electrochemical Biosensor Charge Transfer Limiting Current Measurement

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Solution Overview

Problem

Conventional electrochemical biosensors require longer measurement times and complex electrode systems due to diffusion-limiting methods, which affect accuracy and sensitivity, while microelectrode systems suffer from low sensitivity and necessitate multiple electrodes.

Innovation Solution

A method using an electrochemical biosensor with a reagent layer containing oxidoreductase, electrically conductive particles, and an oxazoline group-containing water-soluble polymer on electrodes, detecting charge transfer limiting current for substance measurement, independent of diffusion processes, allowing for shorter measurement times and higher accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Cottrell current measurement method is used, then measurement accuracy is improved, but measurement time is increased

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidmeasurement time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The invention changes the measurement parameter from diffusion-limited current to charge transfer-limited current by controlling the potential application, thereby achieving accurate measurement without requiring extended diffusion time. The potential is applied within a specific range to ensure charge transfer limitation while maintaining measurement accuracy.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

Instead of measuring diffusion-limited current as in conventional methods, the invention inverts the approach by measuring charge transfer-limited current. This reversal of the limiting mechanism allows for faster measurement while maintaining accuracy, as charge transfer processes occur more rapidly than diffusion processes.

Inventive Principle:

Principle #13The other way round (Inversion)

2Loss of time

If microelectrode system is used, then measurement time is reduced, but sensitivity is decreased

Engineering Contradiction:

Improvemeasurement timeVSAvoidsensitivity

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The invention changes the controlling parameter from diffusion to charge transfer by applying potential within a specific range. This parameter change allows the use of simpler electrode systems while maintaining both fast response and high sensitivity, as the measurement is no longer constrained by diffusion limitations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention inverts the conventional approach by measuring charge transfer-limited current instead of diffusion-limited current. This inversion enables the use of single electrode systems with fast response times while maintaining high sensitivity, eliminating the need for complex multi-electrode configurations.

Inventive Principle:

Principle #13The other way round (Inversion)

3Measurement precision

If diffusion-limiting measurement is used, then measurement accuracy is improved, but system complexity is increased

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidelectrode system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The invention changes the measurement from diffusion-limited to charge transfer-limited by controlling the applied potential. This parameter change simplifies the electrode system requirements while maintaining measurement accuracy, as charge transfer processes can be effectively measured with simpler electrode configurations.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention inverts the measurement approach by measuring charge transfer-limited current rather than diffusion-limited current. This inversion reduces system complexity by eliminating the need for complex multi-electrode systems and diffusion control mechanisms, while preserving measurement accuracy through potential control.

Inventive Principle:

Principle #13The other way round (Inversion)

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 enables faster, more accurate substance measurement without diffusion dependence, simplifying the electrode system and reducing measurement time, while maintaining or improving sensitivity and usability.

Implementation Method 1

detecting a current which is generated due to the transfer of electrons derived from the substance in the sample to the working electrode... the current is a charge transfer limiting current which is generated when electrons are directly transferred from the oxidoreductase to the working electrode

Methodology Applied

Scientific EffectElectron transfer: Redox Reactions

Data Source

PatentEP3032250B1Substance measurement method and measurement device employing electrochemical biosensor

Publication Date: 2023.10.11 ARKRAY INC

Figure 1(A)~1(B)
Figure 2
Figure 3

AI summary

Provided is a method for measuring a substance using a biosensor, the method comprising: introducing a sample containing a substance into an electrochemical measurement cell which comprises an insulating base plate; at least two electrodes formed on the insulating base plate; and a reagent layer that is disposed on at least one of the electrodes and comprises an oxidoreductase; applying a voltage to the electrodes; detecting a charge transfer limiting current which is generated due to the transfer of electrons derived from the substance in the sample to the electrode; and determining the concentration of the substance contained in the sample based on the charge transfer limiting current.