Controlled dispersion and assembly of carbon nanotubes with designed tau-proteinrelated amphiphilic peptides

Abstract of the poster presented at the International Conference on Diamond and Carbon Materials, 7th-11th September, Madrid, Spain.The ability of selected peptides based on the N-acetyl-VQIVXK framework to disperse singlewalled carbon nanotubes (SWCNTs) in aqueous media has been investigated in this work, by means of electron microscopy, circular dichroism, and Raman and near infrared spectroscopies [1]. The peptide VQIVYK is a homologous sequence from tau protein, a microtubule-associated protein which aggregates to produce neurofibrillary tangles in neurons of patients with Alzheimer’s disease and other tauopathies [2, 3]. Our results suggest that amyloidogenic peptides wrap SWCNTs, forming an extensive hydrogen bonded β-sheet network. Peptides that form negligible β-sheet containing amyloid (AcVQIVAK and AcVQIVKK) do not form composites with SWCNTs. Thus, it has been estimated that about 60% of the ability of the peptides studied able to disperse SWCNTs can be attributed to hydrophobicity while the other ~40% can be attributed to the ability of the peptides to form β- sheet on the SWCNT surface. Understanding this peptide-SWCNTs interaction is a key issue toward the design of peptides which eventually may incorporate carbon nanotubes into biodevices