Gold Nanoprobe Diagnostic Kit for DNA Repeat Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nucleic acid amplification tests (NAATs) for detecting drug-resistant pathogens require trained professionals and specialized equipment, leading to delayed results and high costs, making them unsuitable for resource-poor settings, while Gram-stain methods offer poorer sensitivity and specificity, often resulting in missed or misdiagnosis.
Innovation Solution
A nanoprobe-based method using gold nanoparticles functionalized with oligonucleotides complementary to DNA repeat sequences, which reduces nanoprobe aggregation in the presence of target DNA, allowing rapid and sensitive detection without cell culture or DNA amplification, using a magnesium salt as an aggregation agent.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If nucleic acid amplification tests (NAATs) are used for detecting drug-resistant pathogens, then sensitivity and specificity are improved, but device complexity and requirement for trained professionals increase
Solution Approach 1:
The patent replaces complex mechanical and electronic systems (PCR machines, centrifuges, incubators) with a simple chemical-based colorimetric assay using gold nanoparticles. The detection mechanism relies on optical properties of AuNPs and basic chemical reactions (DNA hybridization, salt-induced aggregation) that can be performed without sophisticated equipment, while maintaining high sensitivity through the unique optical properties of nanoparticles.
Solution Approach 2:
The patent changes the physical parameters of the detection system by using gold nanoparticles with specific size ranges (10-50 nm) and surface functionalizations. These parameter changes enable the system to achieve high sensitivity through surface plasmon resonance effects and enhanced DNA hybridization kinetics, while the overall system remains simple and equipment-free.
2Measurement precision
If nucleic acid amplification tests (NAATs) are used for detecting drug-resistant pathogens, then detection sensitivity is improved, but time required for results increases
Solution Approach 1:
The patent performs preliminary action by pre-functionalizing gold nanoparticles with single-stranded DNA probes that are complementary to target pathogen sequences. These pre-prepared nanoprobes can directly hybridize with target DNA in the sample without requiring amplification steps, enabling rapid detection within minutes while maintaining high sensitivity through the high surface area to volume ratio of nanoparticles.
Solution Approach 2:
The patent extracts and eliminates the time-consuming DNA amplification steps (PCR, isothermal amplification) from the diagnostic workflow. By using directly detectable target DNA sequences and gold nanoprobe hybridization, the method achieves rapid results in 10-30 minutes without the 1-8 hour amplification process required by conventional NAATs.
3Device complexity
If Gram-stain based identification is used for pathogen detection, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent uses color changes of gold nanoparticles as the detection readout mechanism. Gold nanoparticles exhibit surface plasmon resonance that causes them to appear red when dispersed and blue when aggregated. This colorimetric change provides a visually detectable signal with high sensitivity, far exceeding the capability of Gram-stain methods, while requiring no sophisticated equipment beyond basic color observation or simple spectrophotometry.
Solution Approach 2:
The patent employs composite materials by functionalizing gold nanoparticles with single-stranded DNA probes to create nanoprobes. This composite structure combines the optical properties of gold nanoparticles with the sequence-specific binding capability of DNA, enabling highly sensitive and specific pathogen detection that far outperforms traditional Gram-stain methods while maintaining operational simplicity.
4Measurement precision
If DNA repeat sequences are targeted by nanoprobes, then measurement precision is improved, but nanoprobe aggregation increases
Solution Approach 1:
The patent applies partial action by using salt-induced aggregation as a readout mechanism rather than a complete aggregation event. By carefully controlling salt concentration and incubation time, the method achieves sufficient aggregation to produce a detectable color change while preventing complete aggregation that would eliminate the signal. This partial aggregation approach maintains detection sensitivity while managing nanoprobe stability.
Solution Approach 2:
The patent changes physical parameters by optimizing salt concentration, temperature, and nanoprobe concentration to balance aggregation and stability. By adjusting these parameters, the system achieves enhanced detection sensitivity through targeted binding to DNA repeat sequences while controlling the degree of aggregation to maintain measurable signal and nanoprobe stability throughout the assay.
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 method achieves an 8-fold improvement in sensitivity, enabling detection of pathogens like Neisseria gonorrhoeae at lower concentrations within 30 minutes, suitable for resource-poor clinics and point-of-care applications.
Implementation Method 1
the oligonucleotide comprises a sequence that is substantially complementary to a portion of the DNA repeat sequence
Implementation Method 2
contacting the test sample with a nanoprobe aggregation agent
Implementation Method 3
AuNP aggregation results in a distinct colour change (from red in a dispersed phase to blue in an aggregated phase; attributed to changes in surface plasmon resonance)
Data Source
AI summary
Detecting target genomic DNA in a test sample, wherein the target genomic DNA comprises a DNA repeat sequence, using a nanoprobe comprising a nanoparticle functionalised by a surface-mounted oligonucleotide, wherein the oligonucleotide comprises a sequence that is substantially complementary to a portion of the DNA repeat sequence, and a nanoprobe and kit related thereto.