Biosensor Bilayered Enzyme Layer for Rapid Neutral Fat Measurement
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Solution Overview
Problem
Current biosensors for measuring neutral fat concentration are not sufficiently rapid or precise, as they require expensive enzymes and lengthy measurement times due to suboptimal enzyme layer configurations.
Innovation Solution
A biosensor with a bilayered structure where a lipid-decomposing enzyme layer is directly applied onto a redox-enzyme-containing layer, enhancing enzyme reaction rates without the need for carriers like filter paper or nonwoven cloths, allowing for quicker penetration and reaction completion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single enzyme layer is used to decompose neutral fat, then the measurement can be performed with simpler structure, but the measurement time becomes excessively long and precision is insufficient
Solution Approach 1:
The enzyme layer is segmented into two distinct layers: a first enzyme layer containing lipoprotein lipase for neutral fat decomposition, and a second enzyme layer containing glycerol dehydrogenase for glycerol oxidation. This segmentation allows each layer to perform its specific function efficiently, reducing overall measurement time while maintaining structural organization.
Solution Approach 2:
The invention transitions from a single-layer enzyme structure to a two-layer enzyme structure, adding a dimensional aspect to the enzyme layer configuration. This layered approach enables sequential enzyme reactions to occur in different spatial zones, improving reaction efficiency and reducing measurement time.
2Measurement precision
If three expensive enzymes (LPL, GK, GPO) are used for neutral fat measurement, then measurement precision can be maintained, but enzyme cost becomes excessively high
Solution Approach 1:
The invention extracts and removes glycerol kinase (GK) from the enzyme system, replacing the traditional three-enzyme system (LPL-GK-GPO) with a simplified two-enzyme system (LPL-GLDH). This extraction eliminates the need for expensive GK while maintaining measurement precision through the use of glycerol dehydrogenase with PQQ prosthetic group.
Solution Approach 2:
The invention employs glycerol dehydrogenase with PQQ prosthetic group, which is more cost-effective than the traditional GK-GPO combination. This enzyme replacement reduces enzyme cost while maintaining the ability to accurately measure neutral fat concentration through glycerol detection.
3Reliability
If carrier materials like filter paper or nonwoven cloths are used to support enzyme layers, then enzyme immobilization is improved, but measurement time increases due to slower substrate penetration
Solution Approach 1:
The invention employs porous polytetrafluoroethylene (PTFE) membrane as the carrier material. The porous structure of the PTFE membrane allows rapid substrate penetration while providing sufficient surface area for effective enzyme immobilization, thus maintaining both measurement speed and enzyme stability.
Solution Approach 2:
The invention changes the physical and chemical parameters of the carrier material by selecting PTFE with specific porosity and hydrophobic properties. This parameter optimization enables fast substrate diffusion through the membrane while maintaining strong enzyme attachment, resolving the contradiction between penetration speed and immobilization stability.
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 configuration enables rapid and precise measurement of neutral fat concentration by improving enzyme reaction rates, reducing measurement time to approximately 45 seconds while maintaining high precision.
Implementation Method 1
the redox enzyme and the electron receptor are dissolved in the sample solution so that an enzyme reaction advances between the substrate and the enzyme. By this enzyme reaction, the substrate is oxidized and simultaneously the electron receptor is reduced.
Implementation Method 2
After the enzyme reaction ends, the reduced electron receptor is electrochemically oxidized. From the oxidation current value obtained at this time, the concentration of the substrate in the sample solution can be calculated.
Implementation Method 3
the neutral fat contained in sample solution is first decomposed into, for example, free fatty acid and glycerol with lipoprotein lipase (LPL)
Data Source
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AI summary
To provide a biosensor capable of measuring the concentration of specific component, such as glucose or neutral fat, in sample in a short time. The biosensor is A biosensor, comprising an insulating base plate, an electrode system containing at least a working electrode and a counter electrode and formed on the insulating base plate, and a sample-supplying section formed on the electrode system, wherein the sample-supplying section has a reaction layer comprising: a first reaction layer formed on the electrode system and containing at least a redox enzyme into which pyrroloquinoline quinone (PQQ), flavin adenine dinucleotide (FAD), or flavin mononucleotide (FMN) is incorporated as a prosthetic group; and a second reaction layer formed by applying, onto the first reaction layer, a solution including a lipid decomposing enzyme.