Dual-Electrode Micro Biosensor for Glucose Interference Reduction
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Solution Overview
Problem
Continuous glucose monitoring systems face interference from substances like ascorbic acid, acetaminophen, uric acid, and glucose analogs, which produce electrochemical signals similar to hydrogen peroxide, leading to unreliable glucose concentration measurements.
Innovation Solution
A micro biosensor with two working electrodes of different conductive materials, where one electrode consumes interferants to reduce interference, allowing the other to obtain accurate glucose concentration measurements by distinguishing between hydrogen peroxide and interferant signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single working electrode is used to measure glucose concentration, then the device structure is simple, but interferants produce electrochemical signals that interfere with measurement accuracy
Solution Approach 1:
The single working electrode is divided into two separate working electrodes with different functions: the first working electrode measures glucose concentration by detecting hydrogen peroxide signals, while the second working electrode eliminates interferants by oxidizing them at a lower potential. This segmentation resolves the contradiction by allowing each electrode to specialize in one function, improving measurement precision while maintaining reasonable device complexity.
Solution Approach 2:
The second working electrode acts as an intermediary that removes interferants (ascorbic acid, acetaminophen, uric acid) before they can interfere with the measurement at the first working electrode. By introducing this intermediate component that selectively consumes interferants, the measurement accuracy at the first electrode is improved without significantly increasing overall system complexity.
2Reliability
If the second working electrode has high sensitivity to hydrogen peroxide, then it can effectively detect interferants, but it will also respond to hydrogen peroxide produced by glucose oxidation, causing measurement interference
Solution Approach 1:
The second working electrode is designed with different local properties: it uses a conductive material (such as carbon or gold) that has high catalytic activity toward interferants like ascorbic acid and acetaminophen, but lower sensitivity to hydrogen peroxide compared to the first electrode. This local quality differentiation allows the second electrode to selectively consume interferants while minimizing its response to hydrogen peroxide, thus resolving the contradiction between interferant elimination effectiveness and measurement accuracy.
Solution Approach 2:
The second working electrode operates at a lower potential (0.2-0.8V) compared to the first electrode (0.6-1.2V), changing the electrochemical parameter to preferentially oxidize interferants before they reach the first electrode. By adjusting the operating potential parameter, the system achieves selective interferant consumption while reducing the electrode's response to hydrogen peroxide, thereby maintaining measurement precision.
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 micro biosensor effectively reduces measurement interference, providing accurate and reliable glucose concentration readings even in the presence of common interferants, as demonstrated by in vitro and in vivo tests.
Implementation Method 1
the first conductive material reacts with the hydrogen peroxide to produce a current signal, and through a value of the current signal corresponding to the concentration, a physiological signal is obtained
Implementation Method 2
when the first working electrode is driven by the first working voltage to cause the first conductive material to react with the interferant to produce an interfering current signal
Implementation Method 3
the second sensing section produce an interference eliminating range, which contacts a surrounding of the first working electrode and at least partially overlaps with the measurement range to consume the interferant for reducing a generation of the interfering current signal
Implementation Method 4
a chemical reagent covered on at least a portion of the first conductive material of the first sensing section for reacting with the glucose in the biofluid to produce hydrogen peroxide
Data Source
AI summary
The present invention provides a micro biosensor for reducing a measurement interference when measuring a target analyte in the biofluid, including: a substrate; a first working electrode configured on the surface, and including a first sensing section; a second working electrode configured on the surface, and including a second sensing section which is configured adjacent to at least one side of the first sensing section; and a chemical reagent covered on at least a portion of the first sensing section for reacting with the target analyte to produce a resultant. When the first working electrode is driven by a first working voltage, the first sensing section measures a physiological signal with respect to the target analyte. When the second working electrode is driven by a second working voltage, the second conductive material can directly consume the interferant so as to continuously reduce the measurement inference of the physiological signal.