Reduced Solubility Enzyme Biosensors for Multi-Use Stability
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Solution Overview
Problem
Current multi-use biosensors have a short use-life due to insufficient active enzyme immobilization, enzyme leaching, and degradation, leading to poor performance and limited sample capability.
Innovation Solution
A multi-use biosensor with a modified enzyme that reduces solubility through reaction with a functional group, such as long chain biotin, is used, which is immobilized by a cover membrane on an electrode, maintaining enzyme activity and integrity over an extended period.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional enzyme immobilization methods (glutaraldehyde cross-linking) are used, then enzyme is retained on the electrode, but enzyme leaching occurs over time leading to short use-life
Solution Approach 1:
The patent changes the chemical parameters of the enzyme by acylating it with long-chain fatty acids (C12-C22), fundamentally altering its solubility properties. This parameter change transforms the enzyme from a water-soluble state to a state that is insoluble in aqueous buffers but soluble in organic solvents, thereby preventing enzyme leaching without requiring cross-linking chemistry.
Solution Approach 2:
The patent introduces an intermediary substance (long-chain fatty acid) that mediates between the enzyme and the electrode environment. This intermediary acylates the enzyme, creating a molecular bridge that confers organic solvent solubility characteristics to the enzyme, preventing its leaching into aqueous sample buffers while maintaining catalytic activity.
2Reliability
If enzyme is immobilized using cross-linking, then enzyme is held in place, but active enzyme amount is insufficient leading to poor performance
Solution Approach 1:
The patent changes the physical state parameters of the enzyme through acylation, transforming it from a cross-linked insoluble form to an acylated form that precipitates in aqueous buffers. This parameter change allows for higher loading of active enzyme on the electrode surface, as the enzyme maintains its native structure and activity while being retained through precipitation rather than cross-linking.
3Productivity
If small sample sizes are used for frequent testing, then sample volume is reduced, but enzyme degradation occurs leading to performance loss
Solution Approach 1:
The patent changes the environmental stability parameters of the enzyme through acylation with long-chain fatty acids. This modification makes the enzyme insensitive to aqueous buffer environments, preventing hydrolysis and degradation that normally occur during frequent use. The acylated enzyme maintains stable activity over extended periods, enabling high sampling frequency without performance degradation.
4Duration of action of stationary object
If traditional immobilization is used, then enzyme is retained initially, but use-based degradation occurs limiting multi-use capability
Solution Approach 1:
The patent changes the chemical stability parameters of the enzyme through acylation, fundamentally altering how the enzyme interacts with aqueous environments. This parameter change prevents use-based degradation by making the enzyme insoluble and stable in buffer solutions, allowing the biosensor to maintain enzyme integrity over extended use periods and enabling true multi-use capability.
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 modified enzyme biosensor achieves a longer use-life of at least 14 days and a higher sample capability of 3000 samples while maintaining precision and response, reducing the need for frequent replacements and minimizing carryover between samples.
Implementation Method 1
modifying an enzyme present in a first buffer by reacting at least one functional group on the enzyme with a reactant, thereby producing a modified enzyme that has a reduced solubility... forming a precipitate of modified enzyme
Implementation Method 2
redissolving the precipitate of modified enzyme in a second buffer to provide a modified enzyme solution, wherein the second buffer has a lower ionic strength than the first buffer, whereby the modified enzyme is substantially soluble in the second buffer
Implementation Method 3
disposing a membrane on at least a portion of the modified enzyme and electrode, wherein the membrane immobilizes the modified enzyme on the electrode
Data Source
AI summary
Multi-use biosensors are disclosed that include enzymes that have been modified to reduce the solubility thereof; the multi-use biosensors are used to detect analytes in fluidic biological samples, and the biosensors also maintain their enzyme activity after many uses. Multi-sensor arrays are disclosed that include multiple biosensors. Also disclosed are methods of producing and using these devices.