Directed Assembly of Multi‐Walled Nanotubes and Nanoribbons of Amino Acid Amphiphiles Using a Layer‐by‐Layer Approach

• Published in: Chemistry : a European journal 2021-04, Vol.27 (23), p.6904-6910
• Main Authors: Siegl, Kathrin, Kolik‐Shmuel, Luba, Zhang, Mingming, Prévost, Sylvain, Vishnia, Kalanit, Mor, Amram, Appavou, Marie‐Sousai, Jafta, Charl J., Danino, Dganit, Gradzielski, Michael
• Format: Article
• Language: English
• Subjects: amino acid amphiphiles; Amino Acids; Cations; Chemistry; Communication; Communications; cryogenic transmission electron microscopy; layer-by-layer assembly; Microscopy, Electron, Transmission; multilayer nanotubes; Nanoribbons; Nanotechnology; Nanotubes; Nanotubes, Carbon; Neutron scattering; Polyelectrolytes; Scattering, Small Angle; small-angle neutron scattering; Surface charge; Transmission electron microscopy
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202005331

Monodisperse unilamellar nanotubes (NTs) and nanoribbons (NRs) were transformed to multilamellar NRs and NTs in a well‐defined fashion. This was done by using a step‐wise approach in which self‐assembled cationic amino acid amphiphile (AAA) formed the initial NTs or NRs, and added polyanion produced an intermediate coating. Successive addition of cationic AAA formed a covering AAA layer, and by repeating this layer‐by‐layer (LBL) procedure, multi‐walled nanotubes (mwNTs) and nanoribbons were formed. This process was structurally investigated by combining small‐angle neutron scattering (SANS) and cryogenic‐transmission electron microscopy (cryo‐TEM), confirming the multilamellar structure and the precise layer spacing. In this way the controlled formation of multi‐walled suprastructures was demonstrated in a simple and reproducible fashion, which allowed to control the charge on the surface of these 1D aggregates. This pathway to 1D colloidal materials is interesting for applications in life science and creating well‐defined building blocks in nanotechnology. Multi‐walled nanotubes and nanoribbons of amino acid amphiphiles are fabricated by using a layer‐by‐layer technique, where successive rigid amphiphile layers are glued together by oppositely charged polyelectrolyte. The resulting well‐defined 1D structures are attractive as potential biocompatible delivery systems and building blocks in nanotechnology.