TY  - JOUR
A1  - Oertel, Jana
A1  - Keller, Adrian
A1  - Prinz, Julia
A1  - Schreiber, Benjamin
A1  - Huebner, Rene
A1  - Kerbusch, Jochen
A1  - Bald, Ilko
A1  - Fahmy, Karim
T1  - Anisotropic metal growth on phospholipid nanodiscs via lipid bilayer expansion
JF  - Scientific reports
N2  - Self-assembling biomolecules provide attractive templates for the preparation of metallic nanostructures. However, the intuitive transfer of the "outer shape" of the assembled macromolecules to the final metallic particle depends on the intermolecular forces among the biomolecules which compete with interactions between template molecules and the metal during metallization. The shape of the bio-template may thus be more dynamic than generally assumed. Here, we have studied the metallization of phospholipid nanodiscs which are discoidal particles of similar to 10 nm diameter containing a lipid bilayer similar to 5 nm thick. Using negatively charged lipids, electrostatic adsorption of amine-coated Au nanoparticles was achieved and followed by electroless gold deposition. Whereas Au nanoparticle adsorption preserves the shape of the bio-template, metallization proceeds via invasion of Au into the hydrophobic core of the nanodisc. Thereby, the lipidic phase induces a lateral growth that increases the diameter but not the original thickness of the template. Infrared spectroscopy reveals lipid expansion and suggests the existence of internal gaps in the metallized nanodiscs, which is confirmed by surface-enhanced Raman scattering from the encapsulated lipids. Interference of metallic growth with non-covalent interactions can thus become itself a shape-determining factor in the metallization of particularly soft and structurally anisotropic biomaterials.
Y1  - 2016
U6  - https://doi.org/10.1038/srep26718
SN  - 2045-2322
VL  - 6
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Prinz, Julia
A1  - Schreiber, Benjamin
A1  - Olejko, Lydia
A1  - Oertel, Jana
A1  - Rackwitz, Jenny
A1  - Keller, Adrian
A1  - Bald, Ilko
T1  - DNA origami substrates for highly sensitive surface-enhanced raman scattering
JF  - The journal of physical chemistry letters
N2  - DNA nanotechnology holds great promise for the fabrication of novel plasmonic nanostructures and the potential to carry out single-molecule measurements using optical spectroscopy. Here, we demonstrate for the first time that DNA origami nanostructures can be exploited as substrates for surface-enhanced Raman scattering (SERS). Gold nanoparticles (AuNPs) have been arranged into dimers to create intense Raman scattering hot spots in the interparticle gaps. AuNPs (15 nm) covered with TAMRA-modified DNA have been placed at a nominal distance of 25 nm to demonstrate the formation of Raman hot spots. To control the plasmonic coupling between the nanoparticles and thus the field enhancement in the hot spot, the size of AuNPs has been varied from 5 to 28 nm by electroless Au deposition. By the precise positioning of a specific number of TAMRA molecules in these hot spots, SERS with the highest sensitivity down to the few-molecule level is obtained.
Y1  - 2013
U6  - https://doi.org/10.1021/jz402076b
SN  - 1948-7185
VL  - 4
IS  - 23
SP  - 4140
EP  - 4145
PB  - American Chemical Society
CY  - Washington
ER  -