Hydration-dependent band gap tunability of self-assembled phenylalanyl tryptophan nanotubes

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 134; p. 114910
• Main Authors: de Souza Freitas, Hugo A., Chaves Neto, Antonio M.J., de Sousa, Francisco Ferreira, Amorim, Rodrigo G., Gester, Rodrigo, Stoyanov, Stanislav R., Rocha, Alexandre Reily, Andrade-Filho, T.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2021
• Subjects: Confined water; DFTB; Peptide system; Stacking interactions; Tunable band gap; Peptide system; Stacking interactions; Tunable band gap; Confined water; DFTB
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2021.114910

Bioinspired peptide nanotubes have emerged as a brand new category of organic semiconductors employed in many nanotechnological applications. Trapped solvent, long-range ordering, and configurational versatility play important roles in the control and tuning of the electronic properties of these nanotubes. Here, the density-functional theory-based tight-binding approach is employed to study the impact of building block separation, caused by confined water molecules, on the geometry and electronic structure of phenylalanyl tryptophan nanotubes (PTNTs). The amount of water in the PTNT walls changes considerably the distance between the building blocks. This structural modification causes a modulation of the PTNT bandgap and changes its nature from indirect to direct. An effective control of the structure and electronic properties of these one-dimensional PTNTs can pave the way for potential applications in bioelectronic and medical devices. •We investigate the structural and electronic properties of peptide nanotubes.•The amount of water confined changes the nanotube stacking behavior.•The structural modification causes the bandgap tuning.•Efficient control of properties is promising for medical applications.