The effect of macrodipole orientation on the piezoelectric response of cyclic β-peptide nanotube bundles on gold substrates

Self-assembly and hydrogel formation ability of Fmoc-dipeptides comprising α-methyl-L-phenylalanine

“…Supramolecular nanostructures, which consist of selfassembling peptide derivatives, have attracted rapidly increasing attention for the fabrication of various biofunctional materials [1][2][3][4][5][6][7][8][9]. Recent seminal works have revealed that short peptides bearing an aromatic group at their N-termini have a robust potential to self-assemble into supramolecular nanostructures under aqueous conditions with subsequent hydrogel formation, facilitating active exploration [10][11][12][13][14][15][16][17].…”

Engineering pH-responsive switching of donor–π–acceptor chromophore alignments along a peptide nanotube scaffold

“…CP3Npi molecules should stack in a columnar arrangement to adopt one mode of nearly parallel stacking of Npi moieties out of three possible modes due to the constraint of stacking of cyclic tri-b-peptides. 28,29 CD spectra also support a regular arrangement of Npi moieties in nanotubes. CP3Npi in HFIP solution shows no Cotton effect around 450 nm in the Npi absorption region, except a negative Cotton effect at 210 nm which is attributed cyclic peptide skeleton (Fig.…”

“…There are three stacking modes with rotations by 0 , 120 , and 240 between rst and second cyclic peptides along PNT. 29 The rotation by 0 of the closest Npi moieties (blue spheres) illustrated in Fig. 4D causes severe electrostatic repulsions whilst other rotations (red spheres illustrated in Fig.…”

Piezoelectric properties reflecting nanostructures of tetrathiafulvalene and chloranil complexes using cyclic peptide nanotube scaffolds

“…Although these values were lower than those of the α-helical 24mer peptide SAM (16 μCm −2 K −1 ) [35] and poly(vinylidene fluoride) (27 μCm −2 K −1 ), [36] they are over 10 times larger than that in a previous report of naphthyl group-containing PNTs (0.27 μCm −2 K −1 ). [22] The large pyroelectric coefficients are therefore ascribable to the polarized charge-transfer complexes. in the ES-type PNT, resulting in resistance against structural distortion in the AA-type PNT more than in the ES-type PNT.…”

“…Two kinds of cyclic peptide skeletons were designed and synthesized, cyclo(β-Asp-β-Ala-β-Ala) or cyclo (β-Lys-β-Ala-β-Ala) (AA-type cyclic peptide, Figure 1B, left) and cyclo(β-Asp-ethylenediamine-succinic acid) or cyclo(β-Lys-ethylenediamine-succinic acid) (ES-type cyclic peptide, Figure 1B, right). [22,23] According to the previous report, the chloranil and TTF groups introduced at the side chains are arranged randomly for a AAtype PNT, and they are arranged in a left-handed helical manner for a ES-type PNT owing to the maximizing the number of intermolecular hydrogen bonds through the PNTs. [23] Combinations of donor/acceptor cyclic peptides, CP3TAA/CP3CAA and CP3TES/CP3CES, were self-assembled into PNTs to form a charge-transfer complex along the PNT ( Figure 1C) and the electronic properties on a gold substrate and piezo-response properties were studied by the current sensing atomic force microscopy (AFM), the Kelvin force microscopy (KFM), and the piezoelectric force microscopy (PFM).…”