Colloidally Stable and Surfactant-Free Protein-Coated Gold Nanorods in Biological Media

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Moritz Tebbe - , University of Bayreuth (Author)
  • Christian Kuttner - , University of Bayreuth (Author)
  • Max Männel - , University of Bayreuth (Author)
  • Andreas Fery - , University of Bayreuth (Author)
  • Munish Chanana - , University of Bayreuth, ETH Zurich (Author)

Abstract

In this work, we investigate the ligand exchange of cetyltrimethylammonium bromide (CTAB) with bovine serum albumin for gold nanorods. We demonstrate by surface-enhanced Raman scattering measurements that CTAB, which is used as a shape-directing agent in the particle synthesis, is completely removed from solution and particle surface. Thus, the protein-coated nanorods are suitable for bioapplications, where cationic surfactants must be avoided. At the same time, the colloidal stability of the system is significantly increased, as evidenced by spectroscopic investigation of the particle longitudinal surface plasmon resonance, which is sensitive to aggregation. Particles are stable at very high concentrations (cAu 20 mg/mL) in biological media such as phosphate buffer saline or Dulbecco's Modified Eagle's Medium and over a large pH range (2-12). Particles can even be freeze-dried (lyophilized) and redispersed. The protocol was applied to gold nanoparticles with a large range of aspect ratios and sizes with main absorption frequencies covering the visible and the near-IR spectral range from 600 to 1100 nm. Thus, these colloidally stable and surfactant-free protein-coated nanoparticles are of great interest for various plasmonic and biomedical applications. (Figure Presented).

Details

Original languageEnglish
Pages (from-to)5984-5991
Number of pages8
JournalACS Applied Materials and Interfaces
Volume7
Issue number10
Publication statusPublished - 18 Mar 2015
Peer-reviewedYes
Externally publishedYes

External IDs

PubMed 25706195

Keywords

ASJC Scopus subject areas

Keywords

  • biocompatible, colloidal stability, CTAB replacement, ligand exchange, lyophilized, protein coating