The study of genomic DNA adsorption and subsequent interactions using total internal reflection ellipsometry.
Alexei Nabok1, Anna Tsargorodskaya, Frank Davis
1Sheffield Hallam University, Materials and Engineering Research Institute, Sheffield S1 1WB, UK.
Biosensors & Bioelectronics
|June 16, 2007
Summary
This study used total internal reflection ellipsometry (TIRE) to analyze DNA adsorption. Identical fish DNA species adsorbed together showed significant thickness increase, unlike different species.
Area of Science:
- Biophysics
- Surface Science
- Molecular Biology
Background:
- Understanding DNA adsorption is crucial for biosensor development and biomaterial functionalization.
- Previous methods lacked the sensitivity to precisely quantify DNA layer interactions.
Purpose of the Study:
- To investigate the adsorption behavior of single-stranded DNA (ssDNA) from different fish species.
- To explore the interactions between adsorbed and solvated DNA layers using a novel optical technique.
Main Methods:
- Utilized total internal reflection ellipsometry (TIRE), combining spectroscopic ellipsometry and surface plasmon resonance (SPR).
- Electrostatic adsorption of herring and salmon ssDNA onto polyethylenimine-coated gold surfaces.
- Atomic Force Microscopy (AFM) for surface roughness analysis.
Main Results:
- Adsorption of identical fish ssDNA species resulted in significant film thickness increases (20-21 nm).
- Adsorption of ssDNA from alternate fish species showed minimal thickness changes (3-5 nm).
- TIRE data on layer thickness correlated well with AFM surface roughness findings.
Conclusions:
- Demonstrated species-specific interactions in DNA adsorption using TIRE.
- The novel TIRE method provides sensitive quantification of DNA layer formation and interactions.
- Findings have implications for designing DNA-based surfaces with controlled properties.
