Quantum Dot Immunoassay for Rapid Multiplex AD Biomarker Detection

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Solution Overview

Problem

Current methods for diagnosing Alzheimer's disease are expensive, time-consuming, and require centralized facilities, failing to detect biomarkers before symptoms appear, and there is a lack of affordable, minimally invasive tools for early detection and monitoring of the disease.

Innovation Solution

A rapid, cost-effective point-of-care (PoC) assay using bioactivated non-magnetic and magnetic quantum dots in a solution phase, enabling multiplexed detection of multiple Alzheimer's disease biomarkers (Aβ1-40, Aβ1-42, tau-protein, and BDNF) directly in a reaction tube, generating visible signals within 10-20 minutes without the need for a glass chip platform.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional centralized diagnostic methods are used, then diagnostic accuracy is improved, but cost and time consumption increase significantly

Engineering Contradiction:
Improvediagnostic accuracyVSAvoidtime consumption
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The diagnostic system is segmented into two functional components: magnetic quantum dots for biomarker capture and non-magnetic quantum dots for signal generation. This segmentation enables parallel processing of multiple biomarkers simultaneously, reducing diagnostic time while maintaining accuracy through multiplexed detection capabilities

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Magnetic quantum dots serve as intermediaries that bridge the gap between sample preparation and detection. They capture biomarkers in the serum sample and present them to non-magnetic quantum dots for optical signal generation, enabling rapid detection without complex centralized processing

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If traditional diagnostic facilities are used, then detection reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improvedetection reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The magnetic quantum dots are extracted and separated from the reaction mixture using an external magnet. This simple extraction step concentrates the biomarker-QD complexes and removes the need for complex centrifugation or filtration systems, reducing device complexity while maintaining reliable detection

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The optical detection system replaces complex mechanical or electrical diagnostic equipment. Non-magnetic quantum dots generate optical signals that can be detected with simple optical components or even visual inspection, substituting sophisticated mechanical diagnostic systems with a simpler optical readout

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If glass chip platforms are used, then signal generation is improved, but manufacturing cost and operational complexity increase

Engineering Contradiction:
Improvesignal generationVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The non-magnetic quantum dots serve multiple functions: they generate optical signals, enable multiplexed detection through different emission wavelengths, and can be used with various magnetic quantum dot configurations. This multi-functionality eliminates the need for specialized glass chip platforms, reducing manufacturing costs while maintaining signal generation capabilities

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes the detection parameter from requiring a solid support platform (glass chip) to using free-floating quantum dot complexes in solution. This parameter change simplifies manufacturing by eliminating precise chip fabrication requirements while maintaining detection sensitivity through the inherent optical properties of quantum dots

Inventive Principle:
Principle #35Parameter changes

4Loss of time

If early detection methods are developed, then diagnostic timing is improved, but detection sensitivity requirements increase

Engineering Contradiction:
Improvediagnostic timingVSAvoiddetection sensitivity
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The system uses composite quantum dot structures combining magnetic and non-magnetic properties. This composite approach enhances detection sensitivity by concentrating multiple functional properties in a single nanoscale platform, enabling reliable detection of low-abundance biomarkers at early disease stages

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The system transitions from detecting single biomarkers to multiplexed detection of multiple biomarkers simultaneously using different quantum dot emission wavelengths. This dimensional expansion in detection capability allows comprehensive early diagnosis through analysis of biomarker patterns, improving sensitivity for detecting early disease manifestations

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

The assay provides accurate, real-time, and semi-quantitative detection of Alzheimer's disease biomarkers in serum, allowing early diagnosis and monitoring of disease progression without specialized equipment, reducing costs and time, and facilitating decentralized healthcare.

Implementation Method 1

The assay utilizes a combination of bioactivated non-magnetic and magnetic quantum dots for rapid immuno-optomagnetic detection of serum biomarkers in free solution

Methodology Applied
Scientific EffectMagnetic separation: Magnetism

Implementation Method 2

generating visible signals within 10-20 minutes

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Implementation Method 3

bioactivated non-magnetic and magnetic quantum dots in a solution phase, enabling multiplexed detection

Methodology Applied
Scientific EffectQuantum dot optical properties: Photoluminescence

Implementation Method 4

multiplexed detection of multiple Alzheimer's disease biomarkers (Aβ1-40, Aβ1-42, tau-protein, and BDNF)

Methodology Applied
Scientific EffectImmunoassay binding: Absorption (physical)

Data Source

PatentEP4409292B1In vitro point-of-care assay method/process using a combination of bioactivated non-magnetic and magnetic quantum dots for rapid immuno-optomagnetic detection of serum biomarkers in free solution
Publication Date: 2025.11.05 SABANCI UNIVERSITESI NANOTEKNOLOJI ARASTIRMA & UYGULAMA MERKEZI
  • EP4409292B1 patent drawingFigure 1
  • EP4409292B1 patent drawingFigure 2
  • EP4409292B1 patent drawingFigure 3(a)~3(c)

AI summary

The current invention is related to detecting risk biomarkers for chronic neurodegenerative disorder of central nervous system called Alzheimer's disease (AD). AD is the most common cause of dementia, and it is characterized by extracellular senile plaques formed by the accumulation of amyloid β (Aβ) proteins and aggregation of tau proteins into intracellular neurofibrillary tangles in central nervous system. The present invention aims at developing a novel PoC based multiple AD biomarkers detection assay and method, such as Aβ1- 40/Aβ1-42, tau protein and BDNF using multi-colored highly luminescent, non-photo-bleaching quantum dots (QDs), which provides an affordable and accurate means for early diagnosis of MCI, AD or dementia at homes, hospitals or near the patient bedsides.