alexa Silica shell gold core nanoparticles: correlating shell thickness with the plasmonic red shift upon aggregation.
Materials Science

Materials Science

Journal of Nanomedicine & Nanotechnology

Author(s): Vanderkooy A, Chen Y, Gonzaga F, Brook MA

Abstract Share this page

Abstract Differences in the wavelengths of the surface plasmon band of gold nanoparticles (AuNP)--before and after particle aggregation--are widely used in bioanalytical assays. However, the gold surfaces in such bioassays can suffer from exchange and desorption of noncovalently bound ligands and from nonspecific adsorption of biomolecules. Silica shells on the surfaces of the gold can extend the available surface chemistries for bioconjugation and potentially avoid these issues. Therefore, silica was grown on gold surfaces using either hydrolysis/condensation of tetraethyl orthosilicate 1 under basic conditions or diglyceroxysilane 2 at neutral pH. The former precursor permitted slow, controlled growth of shells from about 1.7 to 4.3 nm thickness. By contrast, 3-4 nm thick silica shells formed within an hour using diglyceroxysilane; thinner or thicker shells were not readily available. Within the range of shell thicknesses synthesized, the presence of a silica shell on the gold nanoparticle did not significantly affect the absorbance maximum (~5 nm) of unaggregated particles. However, the change in absorbance wavelength upon aggregation of the particles was highly dependent on the thickness of the shell. With silica shells coating the AuNP, there was a significant decrease in the absorbance maximum of the aggregated particles, from ~578 to ~536 nm, as the shell thicknesses increased from ~1.7 to ~4.3 nm, because of increased distance between adjacent gold cores. These studies provide guidance for the development of colorimetric assays using silica-coated AuNP. © 2011 American Chemical Society This article was published in ACS Appl Mater Interfaces and referenced in Journal of Nanomedicine & Nanotechnology

Relevant Expert PPTs

Recommended Conferences

  • Nano Congress for Next Generation
    August 31-September 01, 2017 Brussels,Belgium
  • Graphene & 2D Materials
    September 14-15, 2017 Edinburgh, Scotland
  • Graphene & 2D Materials
    November 6-7, 2017 Frankfurt, Germany
  • World Congress on Nanoscience and Nano Technology
    October 16-17, 2017 Dubai, UAE
  • World Medical Nanotechnology Congress
    October 18-19, 2017 Osaka, Japan
  • Nanoscienceand Molecular Nanotechnology
    Nov 06-08, 2017 Frankfurt, Germany
Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords