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Understanding and improving aggregated gold nanoparticle/dsDNA interactions by molecular spectroscopy and
Jose M Carnerero1, Aila Jimenez-Ruiz, Elia M Grueso
1Department of Physical Chemistry, Faculty of Chemistry, University of Seville. c/ Profesor García González, 1. 41012, Seville, Spain. pradogotor@us.es.
Physical Chemistry Chemical Physics : PCCP
|June 13, 2017
Summary
Double-stranded DNA (dsDNA) bends and interacts with gold nanoparticles (AuNPs) in solution. This discovery enables new methods for detecting dsDNA using AuNP aggregation.
Area of Science:
- Nanotechnology
- Biophysics
- Molecular Biology
Background:
- Single-stranded DNA (ssDNA) readily adsorbs onto gold nanoparticles (AuNPs).
- Double-stranded DNA (dsDNA) exhibits limited affinity for non-functionalized AuNPs.
- Understanding dsDNA-AuNP interactions is crucial for developing new biosensing platforms.
Purpose of the Study:
- To investigate the interaction between long dsDNA and anionic AuNPs.
- To explore the conformational changes of dsDNA in the presence of AuNPs.
- To establish a foundation for dsDNA detection using AuNP aggregation.
Main Methods:
- Dynamic Light Scattering (DLS) to measure changes in DNA size and conformation.
- Viscometry to assess alterations in DNA solution properties.
- Atomic Force Microscopy (AFM) for direct visualization of DNA-AuNP interactions.
- UV-Vis spectroscopy with deconvolution to analyze nanoparticle aggregation states.
Main Results:
- Long dsDNA undergoes significant bending and conformational changes near anionic AuNPs.
- A notable decrease in dsDNA persistence length was observed in the absence of salt.
- dsDNA interaction with AuNPs was confirmed, challenging previous assumptions.
- AuNP aggregation, induced by salt, was found to decrease with increasing dsDNA concentration.
Conclusions:
- dsDNA can interact with anionic AuNPs, facilitated by conformational changes.
- The study provides a basis for novel dsDNA detection methods utilizing AuNP aggregation.
- This research opens avenues for sensitive and specific detection of dsDNA in solution.
