Lateral-Flow Test Strip with Dual Capture Agents for Antibiotic Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Lateral-flow test strips for detecting antibiotic residues in foods often exhibit overly sensitive responses due to multianalyte binders having excessive affinity, leading to false positives and reduced sensitivity to desired detection levels.

Innovation Solution

A method involving a combination of labeled specific and multianalyte binders, where the specific binder has affinity to fewer analytes than the multianalyte binder, is used to adjust test sensitivity by incorporating a test strip with two capture agents that capture the binders differently, allowing for reduced sensitivity to analytes with excessive affinity while maintaining or increasing sensitivity to other analytes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a multianalyte binder with high affinity is used to detect multiple analytes, then the detection range is expanded, but the sensitivity becomes overly high leading to false positives

Engineering Contradiction:
Improvedetection rangeVSAvoidsensitivity
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The test strip is segmented into multiple test zones, each containing capture agents specific to different analytes. The multianalyte binder is distributed across these zones, allowing each zone to detect specific analytes independently. This segmentation enables the system to maintain broad detection range while controlling sensitivity for each individual analyte through localized capture mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different test zones are designed with different local qualities - each zone has capture agents with specific affinity characteristics tailored to the target analyte in that zone. This allows the multianalyte binder to exhibit appropriate sensitivity for each analyte type locally, preventing universal over-sensitivity while maintaining versatility across multiple analyte detections.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If the affinity between binder and analyte is increased to improve detection sensitivity, then detection sensitivity is improved, but false positives increase due to overly sensitive response

Engineering Contradiction:
Improvedetection sensitivityVSAvoidfalse positive rate
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

Capture agents are introduced as intermediary molecules between the multianalyte binder and the analyte. These capture agents are immobilized on the test strip and serve as mediators that facilitate specific binding. The affinity between the binder and analyte is modulated through the capture agent interface, allowing high detection sensitivity while preventing false positives through controlled interaction mechanisms.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The binding system is designed with dynamic characteristics where the multianalyte binder can reversibly bind to different analytes with varying affinities. The system dynamically adjusts binding based on analyte concentration and competition, allowing sensitive detection of low-concentration analytes while preventing false positives through reversible binding equilibrium that favors specific high-affinity interactions.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If a single multianalyte binder is used to detect multiple analytes, then device complexity is reduced, but sensitivity adjustment for individual analytes becomes difficult

Engineering Contradiction:
Improvenumber of bindersVSAvoidsensitivity adjustment
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system transitions from adjusting sensitivity through binder selection (one dimension) to adjusting sensitivity through spatial distribution and concentration control in multiple test zones (another dimension). The single multianalyte binder is distributed across multiple zones with different capture agent concentrations and specificities, enabling independent sensitivity adjustment for each analyte without requiring multiple different binders.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 approach enables detection of analytes at desired regulatory levels by inversely relating the combined binder amount in the test zone to the analyte concentration, reducing false positives and maintaining sensitivity to relevant analytes, thus improving the accuracy of antibiotic residue detection in food samples.

Implementation Method 1

the labeled specific binder having affinity to fewer than all the analytes to which the labeled multianalyte binder has affinity and the labeled multianalyte binder having affinity for (i) at least one analyte to which the labeled specific binder has affinity and (ii) at least one analyte to which the labeled specific binder has less affinity than does the labeled multianalyte binder

Methodology Applied
Scientific EffectAffinity binding:

Implementation Method 2

contacting the admixture with a test strip, the test strip configured to allow lateral flow of the admixture from a first end of the test strip to a second end of the test strip

Methodology Applied
Scientific EffectLateral flow: Capillary Action

Implementation Method 3

a first test zone capture agent having affinity for the labeled specific binder when the labeled specific binder is unbound by an analyte from the sample and a second test zone capture agent having affinity for the labeled multianalyte binder when the labeled multianalyte binder is unbound by an analyte from the sample

Methodology Applied
Scientific EffectAffinity binding:

Data Source

PatentEP2446270B1Method and test strip for detection of residues
Publication Date: 2018.11.21 CHARM SCIENCES INC
  • EP2446270B1 patent drawingFigure 1
  • EP2446270B1 patent drawingFigure 2
  • EP2446270B1 patent drawingFigure 3

AI summary

A method, test strip and method of manufacturing a test strip useful for detecting one or more analytes, such as an antibiotic, in a test sample such as a milk sample. The test strip and method include a labeled specific binder and test capture agent for the specific binder that increases test sensitivity to the analyte for which the specific binder has affinity while decreasing test sensitivity to an analyte for which a multianalyte binder has affinity.