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Updated: Aug 9, 2026
07:37
Single-Molecule Real-Time Visualization of DNA Unwinding by CMG Helicase
Published on: September 27, 2024
Controlling DNA orientation on mixed ssDNA/OEG SAMs
Christina Boozer1, Shengfu Chen, Shaoyi Jiang
1Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA.
Summary
This study introduces mixed self-assembled monolayers (SAMs) of single-stranded DNA (ssDNA) and oligo(ethylene glycol) (OEG) thiols. Optimizing OEG concentration balances ssDNA surface coverage and orientation for improved hybridization and protein resistance.
Area of Science:
- Materials Science
- Biotechnology
- Surface Chemistry
Background:
- Self-assembled monolayers (SAMs) are crucial for surface functionalization.
- Controlling the density and orientation of immobilized biomolecules is key for biosensor performance.
- Oligo(ethylene glycol) (OEG) is known for its protein-repellent properties.
Purpose of the Study:
- To develop and characterize mixed SAMs of single-stranded DNA (ssDNA) and OEG thiols.
- To investigate the effect of OEG concentration on ssDNA surface coverage, orientation, and hybridization efficiency.
- To evaluate the protein resistance of the developed ssDNA/OEG SAMs.
Main Methods:
- Simultaneous coadsorption of ssDNA- and OEG-terminated thiols to form mixed SAMs.
- Electron spectroscopy for chemical analysis (ESCA) to quantify ssDNA surface coverage.
- Surface plasmon resonance (SPR) sensing to measure ssDNA hybridization and protein resistance.
Main Results:
- OEG concentration in the assembly solution directly controls ssDNA surface coverage.
- Higher OEG concentrations lead to lower ssDNA coverage but more favorable probe orientation.
- Hybridization efficiency is governed by a balance between ssDNA coverage and orientation.
- The ssDNA/OEG SAMs exhibit enhanced protein resistance compared to other SAMs.
Conclusions:
- Mixed ssDNA/OEG SAMs offer tunable control over surface properties for biosensing applications.
- The OEG component significantly enhances the protein resistance of ssDNA-functionalized surfaces.
- This approach provides a versatile platform for developing robust and sensitive biosensors.
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