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Gold Nanoparticle Synthesis
Published on: July 10, 2021
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How Fast Can Thiols Bind to the Gold Nanoparticle Surface?
Amanda Bard1, Rebeca Rondon1, Daniela T Marquez1
1Department of Chemistry and Biomolecular Sciences, Centre for Advanced Materials Research (CAMaR), University of Ottawa, Ottawa, ON, Canada.
Photochemistry and Photobiology
|September 8, 2018
Summary
Surface modification of gold nanoparticles with thiols is slow, often exceeding one hour. Fluorescence spectroscopy and SERS studies confirm this, recommending extended incubation times for complete thiol or disulfide binding.
Area of Science:
- Nanotechnology
- Surface Chemistry
- Spectroscopy
Background:
- Gold nanoparticles (AuNPs) are widely used in various applications.
- Surface modification is crucial for tailoring AuNP properties.
- Understanding the kinetics of surface modification is essential for reproducible results.
Purpose of the Study:
- To investigate the kinetics of gold nanoparticle surface modification with thiols.
- To establish reliable methods for monitoring and determining the completion of surface modification.
- To provide recommendations for optimal incubation times for thiol and disulfide functionalization.
Main Methods:
- Fluorescence spectroscopy using 7-mercapto-4-methylcoumarin as a molecular probe.
- Surface-Enhanced Raman Spectroscopy (SERS) studies with aromatic thiols.
Main Results:
- The surface modification of gold nanoparticles with thiols is a slow process, often requiring more than one hour for completion.
- Fluorescence spectroscopy effectively tracks the modification process, serving as a reliable method for determining relative kinetics.
- SERS studies corroborate the slow kinetics observed via fluorescence spectroscopy, confirming the slow formation of thiolate bonds.
Conclusions:
- Thiolate bond formation on gold nanoparticle surfaces is kinetically slow.
- An incubation time of 1-2 hours is recommended for essential completion of thiol binding.
- Overnight incubation is suggested for complete disulfide binding to gold nanoparticle surfaces.
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