10.1021/acsami.5b00335.s001
Moritz Tebbe
Moritz
Tebbe
Christian Kuttner
Christian
Kuttner
Max Männel
Max
Männel
Andreas Fery
Andreas
Fery
Munish Chanana
Munish
Chanana
Colloidally
Stable and Surfactant-Free Protein-Coated Gold Nanorods in Biological
Media
American Chemical Society
2015
Colloidally Stable
particle surface
absorption frequencies
Biological MediaIn
CTAB
gold nanorods
spectroscopic investigation
cationic surfactants
particle synthesis
phosphate buffer saline
1100 nm
ligand exchange
surface plasmon resonance
cetyltrimethylammonium bromide
gold nanoparticles
aspect ratios
serum albumin
2015-12-17 07:39:01
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Colloidally_Stable_and_Surfactant_Free_Protein_Coated_Gold_Nanorods_in_Biological_Media/2049066
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 (<i>c</i><sub>Au</sub> 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.