Electrochemical Lateral Flow Biosensor for Quantitative Detection
Solution Overview
Problem
Current lateral flow immunoassays are limited by their inability to provide quantitative measurements and are prone to false positive results, requiring additional instrumentation and complex procedures, which hinders their use in rapid and portable diagnostics.
Innovation Solution
Integration of electrochemical methods into lateral flow technology using an electrochemical lateral flow biosensor (ELFB) strip with a polymeric hydrophobic membrane, conjugation pad, sampling pad, screen-printed electrode, and wick pad, allowing for single-step analyte detection and reduced false positives through amperometric signals without the need for enzymatic reactions or chemical treatment of samples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional lateral flow immunoassay is used, then the test is simple and rapid, but quantitative measurement capability is lost
Solution Approach 1:
The patent merges the simplicity of lateral flow immunoassay with the quantitative measurement capability of electrochemical sensors by integrating a screen-printed electrode directly onto the test strip membrane, allowing both qualitative visual reading and quantitative electrochemical detection from the same assay platform
Solution Approach 2:
The test strip is designed to serve multiple functions: it can be read visually by untrained personnel for rapid qualitative results, and simultaneously provides quantitative measurements through electrochemical detection at the screen-printed electrode, making the device universally applicable for both point-of-care and laboratory settings
2Reliability
If enzymatic reactions are used for detection, then signal amplification is achieved, but device complexity and procedure time increase
Solution Approach 1:
The patent extracts and eliminates the enzymatic reaction step from the traditional immunoassay protocol by using electroactive labels that directly interact with the screen-printed electrode, removing the need for substrate addition, incubation, and enzymatic conversion steps while maintaining signal amplification capability
Solution Approach 2:
The patent replaces the biochemical enzymatic reaction system with an electrochemical detection system where electroactive labels directly transfer electrons to the electrode, substituting complex enzymatic mechanisms with simpler electrochemical principles for faster and more direct detection
3Measurement precision
If chemical treatment of samples is required, then detection accuracy improves, but ease of operation deteriorates
Solution Approach 1:
The patent implements self-service by designing the assay to automatically perform sample preparation and detection functions through the inherent properties of the electrochemical system, where the screen-printed electrode directly detects electroactive species in the sample without requiring external chemical treatment or complex sample processing steps
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 ELFB strip enables quantitative, rapid, and portable detection of bacterial, viral infections, and toxins with reduced false positives, maintaining simplicity and long shelf life, suitable for untrained personnel, and can be applied to various biological systems.
Implementation Method 1
The labelled conjugate interacts with the specific analyte contained in the sample, thereby initiating the intermolecular interactions, which are dependent on the affinity and avidity of the reagents. The electrochemically active component transfers the electrons to the electrode under its reduction potential, and the galvanometric signal is transmitted to the detector unit.
Implementation Method 2
The liquid sample containing the tested analyte, such as antigen or antibody is added onto the sampling pad, passes to the conjugate pad, and initially reacts with a biorecognition element
Data Source
Figure 1
Figure 2A~2B
Figure 3
AI summary
The electrochemical lateral flow biosensor (ELFB) comprising a novel ELFB strip and electronic detector unit, to which said strip is connected using cable or wirelessly. The strip is made of (a) polymeric hydrophobic membrane, wherein said membrane provides a solid support and enables the capillary flow along the strip; (b) conjugation pad, wherein said pad is placed over and in contact with said membrane at one end of the strip and contains formulation of the adsorbed dehydrated labelled conjugate particles, wherein said conjugate particles are coated with the biorecognition element of the assay and coated or filled with the electrochemically active component (EAC); (c) sampling pad, wherein said pad is placed on top of and in contact with said conjugation pad and provides adsorption of the liquid sample; (d) screen-printed electrode (SPE), wherein said electrode is coated with the immobilised capture antibodies; and (e) wick pad, wherein said pad is placed on top and in contact with said SPE and provides absorption of excess reagents maintaining a lateral flow along the strip. The ELFB can be used for rapid and early detection and quantity analysis of bacterial, parasitic, viral infections, and tumours in biological liquids, toxins, mycotoxins, explosives and other pollutants in wastewater.