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Updated: Jun 6, 2026
08:56
Visual Detection of Multiple Nucleic Acids in a Capillary Array
Published on: November 15, 2017
Nanoparticle probes and mid-infrared chemical imaging for DNA microarray detection.
Magdi M Mossoba1, Sufian F Al-Khaldi, Brianna Schoen
1Division of Analytical Chemistry, Office of Regulatory Science, Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740-3835, USA. magdi.mossoba@fda.hhs.gov
Applied Spectroscopy
|November 16, 2010
Summary
This study introduces mid-infrared chemical imaging (IRCI) for detecting DNA microarrays on glass slides. This novel, sensitive method advances oligonucleotide probe analysis and microarray diagnostics.
Area of Science:
- Analytical Chemistry
- Biotechnology
- Spectroscopy
Background:
- Mid-infrared (IR) spectroscopy for oligonucleotide analysis is typically limited by sensitivity, restricting studies to single probes on specialized substrates.
- Conventional glass slides and microarray spotters are widely available but underutilized for sensitive IR-based detection.
- Developing sensitive, label-free methods for DNA microarray analysis is crucial for advancing diagnostics and research.
Purpose of the Study:
- To apply mid-infrared chemical imaging (IRCI) for the first time to detect nanostructure-based DNA microarrays on standard glass slides.
- To demonstrate a novel, sensitive, and fluorophore-free method for visualizing DNA hybridization in microarrays.
- To explore the potential of IRCI for both qualitative and quantitative analysis of DNA microarrays.
Main Methods:
- Utilized standard glass slides and a microarray spotter to create DNA spots.
- Immobilized alkyl amine-modified oligonucleotide probes on pre-functionalized glass slides.
- Employed a molecular, fluorophore-free approach involving gold-nanoparticle-streptavidin conjugates and silver enhancement for visualization of hybridized DNA targets.
Main Results:
- Successfully applied mid-infrared chemical imaging (IRCI) in external reflection mode for DNA microarray detection on glass slides.
- Demonstrated a novel method for visualizing DNA hybridization via silver enhancement of gold nanoparticles, creating a reflective substrate.
- Achieved discrimination between diffuse and specular reflection modes using IRCI, indicating promising qualitative results.
Conclusions:
- Mid-infrared chemical imaging (IRCI) offers a sensitive and novel approach for detecting DNA microarrays on accessible glass slide substrates.
- The developed fluorophore-free method, utilizing nanostructures and silver enhancement, provides a viable platform for DNA hybridization detection.
- The study presents a proof-of-concept with promising qualitative findings, paving the way for quantitative applications in DNA microarray analysis.
Related Concept Videos
02:34DNA Microarrays
Microarrays are high-throughput and relatively inexpensive assays that can be automated to analyze large quantities of data at a time. They are used in genome-wide studies to compare gene or protein expression under two varied conditions, such as healthy and diseased states. Microarrays consist of glass or silica slides on which probe molecules are covalently attached through surface functionalization. Most commonly, the slides are prepared through the chemisorption of silanes to silica...
03:31Labeling DNA Probes
DNA probes are fragments of DNA labeled with a reporter tag to enable their detection or purification. The resulting labeled DNA probes can then hybridize to target nucleic acid sequences through complementary base-pairing, and may be used to recover or identify these regions.
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...
Radioisotopes, fluorophores, or small molecule binding partners like biotin or digoxigenin, are the most widely used reporter tags for labeling DNA probes. These labels can be attached to the probe DNA molecule via...