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Synthesis and Characterization of Amphiphilic Gold Nanoparticles
Published on: July 2, 2019
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Characterizing the Surface Coverage of Protein-Gold Nanoparticle Bioconjugates
Rachel Kozlowski1, Ashwin Ragupathi1, R Brian Dyer1
1Department of Chemistry , Emory University , Atlanta , Georgia 30322 , United States.
Bioconjugate Chemistry
|July 14, 2018
Summary
Developing new methods to measure protein on gold nanoparticles (AuNPs) is crucial for optimizing bioconjugates. Higher protein coverage was observed on smaller AuNPs due to increased surface curvature.
Area of Science:
- Bioconjugation Chemistry
- Nanomedicine
- Biotechnology
Background:
- Enzyme-nanoparticle bioconjugates are vital for drug delivery and biosensing.
- Current characterization methods struggle to accurately quantify low protein concentrations on nanoparticles.
Purpose of the Study:
- To develop an integrated methodology for characterizing protein-gold nanoparticle (AuNP) bioconjugates.
- To accurately quantify protein content and surface coverage on AuNPs.
Main Methods:
- Site-specific covalent attachment of single-cysteine dihydrofolate reductase mutants to AuNPs (5, 15, 30 nm).
- Utilized SDS-PAGE, UV-vis spectrophotometry, dynamic light scattering, and a novel fluorescence-based assay.
- Calculated surface coverage using accurate protein and AuNP concentration determination.
Main Results:
- Developed a novel fluorescence method for precise low-concentration protein quantification on AuNPs.
- Demonstrated that protein surface coverage on AuNPs is dependent on surface curvature.
- Higher surface coverage was observed on AuNPs with greater surface curvature (smaller diameter).
Conclusions:
- The integrated characterization methodology enables accurate structural and activity assessment of protein-AuNP bioconjugates.
- Understanding surface coverage is critical for optimizing the functionality of enzyme-nanoparticle conjugates.
- This work provides essential tools for advancing applications in nanobiotechnology.
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