Self-Assembly and Electrical Conductivity of a New [1]benzothieno[3,2-b][1]-benzothiophene (BTBT)-Peptide Hydrogel

The conjugation of small-molecule semiconductors with self-assembling peptides is a powerful tool for the fabrication of supramolecular soft materials for organic electronics and bioelectronics. Herein, we introduced the benchmark organic semiconductor [1]benzothieno[3,2-b][1]-benzothiophene (BTBT) within the structure of a self-assembling amphipathic peptide. The molecular structure of the conjugate was rationally designed to favour pi-pi stacking between BTBT cores and pi-delocalization within the self-assembled architectures. Hydrogels with fibrillar structure were obtained upon self-assembly. Spectroscopic studies confirmed that both hydrogen bonding between peptide segments and pi-pi stacking between BTBT chromophores are responsible for the formation of the 3D fibrillar network observed by transmission electron microscopy. The hydrogel was successfully deposited on gold interdigitated electrodes and a conductivity up to 1.6 (+/- 0.1) x 10(-5) S cm(-1) was measured.

Automated summary

The conjugation of small-molecule semiconductors with self-assembling peptides facilitates the fabrication of supramolecular soft materials for organic electronics and bioelectronics. In this study, the benchmark organic semiconductor benzothieno[3,2-b][1]-benzothiophene (BTBT) was introduced into a self-assembling amphipathic peptide structure. The resulting hydrogels exhibited a fibrillar structure, and spectroscopic studies confirmed that hydrogen bonding and pi-pi stacking were responsible for the observed 3D fibrillar network. The hydrogel showed conductivity when deposited on gold interdigitated electrodes, with a measured value of 1.6 (+/- 0.1) x 10(-5) S cm(-1).