1 Biomedical Micro Systems Section, Department of Micro- and Nanotechnology, Technical University of Denmark2 Department of Micro- and Nanotechnology, Technical University of Denmark3 Nano-Bio Integrated Systems Group, Biomedical Micro Systems Section, Department of Micro- and Nanotechnology, Technical University of Denmark4 University of Crete5 Copenhagen Center for Health Technology, Center, Technical University of Denmark
In this report electrostatic force microscopy (EFM) is used to study different peptide self-assembled structures, such as tubes and particles. It is shown that not only geometrical information can be obtained using EFM, but also information about the composition of different structures. In particular we use EFM to investigate the structures of diphenylalanine peptide tubes, particles, and CSGAITIG peptide particles placed on pre-fabricated SiO2 surfaces with a backgate. We show that the cavity in the peptide tubes could be to the presence of water residues. Additionally we show that self-assembled amyloid peptides form spherical solid structures containing the same self-assembled peptide in its interior. In both cases transmission electron microscopy is used to verify these structures. Further, the limitations of the EFM technique are discussed, especially when the observed structures become small compared to the radius of the AFM tip used. Finally, an agreement between the detected signal and the structure of the hollow peptide tubes is demonstrated.
Scanning, 2011, Vol 33, Issue 4, p. 201-207
Self-assembly; Electrostatic force microscopy; Peptide nanoparticles; Peptide nanotubes