Urine Aβ Test Strip Using Colloidal Gold for Early MCI Screening
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for detecting amyloid beta (Aβ) in urine are not practical, sensitive, or specific enough for early diagnosis of Alzheimer's disease (AD), and existing biomarkers like Aβ in cerebrospinal fluid or plasma require invasive procedures or specialized equipment, making them unsuitable for general population screening.
Innovation Solution
A test strip using a polyvinyl chloride (PVC) bottom plate with a sequence of pads coated with colloidal gold particles, Aβ-binding polymers, and antibodies for capturing and detecting Aβ in urine, including a sample pad, conjugation pad, chromatography pad, and absorbent pad, with a test line and control line for visual detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sandwich ELISA or competitive ELISA is used to detect Aβ in urine, then the detection method is established, but the sensitivity and specificity are insufficient due to the small target antigen size and non-specific binding
Solution Approach 1:
The patent introduces an Aβ-specific antibody as an intermediary to capture Aβ from urine samples. This antibody acts as a mediator that specifically binds to Aβ, enabling its isolation and detection despite the small antigen size and non-specific binding issues. The antibody-antigen complex is then detected using colloidal gold labeling, which provides visual detection capability.
Solution Approach 2:
The patent employs colloidal gold particles that exhibit color changes based on their aggregation state. When Aβ is present in the urine sample, it binds to the antibody-conjugated colloidal gold, causing a color change from red to purple/blue at the test line. This colorimetric detection method provides high sensitivity and visual readability without requiring complex instrumentation.
2Measurement precision
If Aβ detection in urine is performed using current methods, then detection is possible, but the detection limit is not met due to extremely-low concentration of Aβ in human urine
Solution Approach 1:
The detection process is segmented into multiple stages: (1) Aβ capture by antibody-conjugated colloidal gold in the sample pad, (2) separation and concentration at the test line through chromatography, and (3) visual detection of the accumulated complex. This segmentation allows trace amounts of Aβ to be concentrated and detected visually, achieving a detection limit suitable for urine samples.
Solution Approach 2:
The patent transitions from solution-phase detection to surface-based detection by using a lateral flow strip. The Aβ-antibody-colloidal gold complex is transported and concentrated on the two-dimensional surface of the test line, allowing visual detection of extremely low concentrations that would be difficult to detect in the three-dimensional urine solution.
3Measurement precision
If invasive methods like CSF analysis or specialized PET/MRI equipment are used for AD diagnosis, then diagnostic accuracy is improved, but patient compliance and accessibility deteriorate
Solution Approach 1:
The patent employs a disposable lateral flow test strip that is inexpensive to manufacture and use. Each strip contains pre-assembled antibody-conjugated colloidal gold and detection reagents that are stable at room temperature. The strip is discarded after a single use, eliminating the need for expensive equipment, specialized facilities, and complex operational procedures, thereby greatly improving patient compliance and accessibility.
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 test strip provides rapid, economical, and sensitive detection of Aβ in urine, suitable for routine clinical examinations and general screening, assisting in the early diagnosis of mild cognitive impairment (MCI) and predicting the risk of AD with high sensitivity and specificity.
Implementation Method 1
The conjugation pad (2) is coated with colloidal gold particles conjugated to a monoclonal antibody; the test line (5) is coated with an Aβ-binding polymer
Implementation Method 2
a sample pad (1), a conjugation pad (2), a chromatography pad (3) and an absorbent pad (4) that are overlapped in sequence
Data Source
AI summary
A test strip for detecting Aβ in urine includes a polyvinyl chloride (PVC) bottom plate. The PVC bottom plate is laid with a sample pad, a conjugation pad, a chromatography pad, and an absorbent pad that are overlapped in sequence. The conjugation pad is coated with colloidal gold particles conjugated to a monoclonal antibody. The chromatography pad is provided with a test line on the side proximate to the conjugation pad, and is provided with a control line on the side proximate to the absorbent pad. The test line is coated with an Aβ-binding polymer. The control line is coated with a goat anti-mouse IgG polyclonal antibody. The method is suitable for the following: routine clinical pathological examination; general screening of a large number of people and self-screening of home end-users; assisting the early diagnosis and prejudgment of mild cognitive impairment (MCI) clinically.