Dielectrophoresis-Based Target Substance Detection Method
Solution Overview
Problem
Existing optical detection methods for target substances, such as viruses, face challenges in distinguishing between specific and non-specific adsorption, leading to false positives and decreased detection accuracy.
Innovation Solution
A detection method involving the formation of a complex between a target substance and a dielectric particle modified with a substance that specifically binds to the target substance, followed by separation of the complex and unbound particles using dielectrophoresis, and subsequent detection using an imaging element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bound body is formed by non-specific adsorption in which a magnetic particle and a fluorescent particle bind to each other without any target substance, then the bound body moves and emits fluorescence, but it is difficult to distinguish this bound body from a bound body including the target substance, leading to false positives and decreased detection accuracy
Solution Approach 1:
The invention separates the detection process into distinct stages: first forming complexes specifically, then separating them from unbound particles through dielectrophoresis before detection. This segmentation allows specific complexes to be isolated and identified, preventing false positives from non-specific adsorption events.
Solution Approach 2:
The invention introduces dielectrophoresis as an intermediary separation mechanism between complex formation and detection. This intermediary step uses dielectric properties to distinguish specific complexes from non-specific bound bodies, enabling accurate identification of target substance-containing complexes while eliminating false positives.
2Measurement precision
If optical detection is performed by measuring signal decrease in response to magnetic field application, then target substance detection is achieved, but non-specific adsorption causes bound bodies to move and emit fluorescence, making distinction difficult
Solution Approach 1:
The invention replaces the magnetic field-based mechanical manipulation system with a dielectrophoresis-based separation system. Instead of relying on magnetic field-induced movement that cannot distinguish specific from non-specific bound bodies, dielectrophoresis uses dielectric property differences to achieve selective separation and identification of specific complexes.
Solution Approach 2:
The invention changes the detection parameter from magnetic field response to dielectric property-based separation. By measuring dielectric properties and using dielectrophoresis to separate complexes based on these properties, the system achieves more reliable target substance detection while reducing false positives from non-specific adsorption.
Data Source
AI summary
A target substance detection method includes forming a complex by causing a target substance and a dielectric particle to bind to each other, the dielectric particle being modified with a substance having a property of specifically binding to the target substance; separating the complex and an unbound particle from each other in a liquid by dielectrophoresis, the unbound particle being a dielectric particle not constituting the complex; and detecting the target substance included in the separated complex by using an imaging element.