Redox-triggered changes in the self-assembly of a ferrocene–peptide conjugate

Abstract

Ultrasonication of a ferrocene conjugate of a short amyloid peptide (Aβ18-20) in toluene causes formation of an organogel, which undergoes dramatic structural changes upon oxidation from a nanofibrillar network to spherical micelles. This morphological change is redox-controlled and reversible.

Vice versa donor acceptor fluorene–ferrocene alternate copolymer: a twisted ribbon for electrical switching

“…11 Selective substitutions by electron donating dialkyl or electron withdrawing dicyano derivative in 9-position of fluorene (Fl) can make these either electronically rich fluorenes or electronically poor fluorenes, respectively. In this consequence, two new conjugated polymers (Scheme 1) where functionalized Fl moieties would serve the role of donor (PFFC-1) and acceptor (PFFC-2) viceversa have been designed to study the oxidation behaviour of Fc of two polymers by common oxidizing agents 12 as well as the switching behaviour of donor-acceptor conjugated polymers that are scarcely seen in the literature 13,14 . In this aspect, we have synthesized fluorene-ferrocene based two donor-acceptor copolymers to explore by their photophysical, morphological, cyclic voltammetry and electrical behaviours supported by theoretical studies.…”

On the Role of Chirality in Guiding the Self‐Assembly of Peptides

“…[33] For 3 and 6,t he average tan d values were 0.38 and 0.24, respectively,b ut aged gels from the same sample showed enhanced tan d values as 0.99 and 0.61, respectively (Supporting Information, Figure S27), which confirmed that the heterochiral gels lose their gelation properties with time. [22,28,29] It was observed that the position of amide-proton signals of individual organogels shifted upfield as the temperature approached T gel .VTNMR studies for all Fc-based organogels unambiguously support as trong hydrogen bonding interaction in the gel state.The T gel of the organogel obtained from 9 is much higher than those of all Fc-based gels,t herefore,t he Molecular recognition is ap rocess in which am olecule selectively recognizes and binds to another substrate molecule through various non-covalent interactions. Va riabletemperature 1 HNMR experiments (VT NMR) were performed on all Fc-gels in toluene (Supporting Information, Figure S30) from 20 to 60 8 8C( above T gel ).…”

“…Them elting temperatures of the self-supportable gels (T gel )r ange from 47 to 98 8 8C. Fc-Gels [28,29] obtained from 1, 3, 4,a nd 6 were at ransparent yellow color.I na ddition, the gel obtained from Py-based peptide 9 was transparent and colorless.H owever, though heterochiral gels 3 and 6 were initially transparent, they started to become opaque after 30-60 min with loss of solvent, indicating its metastable [30] gelation ability (Figure S20 b). Fc-Gels [28,29] obtained from 1, 3, 4,a nd 6 were at ransparent yellow color.I na ddition, the gel obtained from Py-based peptide 9 was transparent and colorless.H owever, though heterochiral gels 3 and 6 were initially transparent, they started to become opaque after 30-60 min with loss of solvent, indicating its metastable [30] gelation ability (Figure S20 b).…”

Redox‐Active Dynamic Self‐Supporting Thixotropic 3D‐Printable G‐Quadruplex Hydrogels

“…Boronate ester mediated LMW G4 hydrogels are dynamic, self-healablea nd thixotropic in nature owing to the dynamic behaviour of the boronic acid-boronate ester equilibrium in aqueous medium. [24] Most of the reported ferrocene-based hydrogels are stimuli responsive where the redox behaviour is controlledb ye xternal stimuli. [23] The oxidised hydrophilic ferrocinium is soluble in water.N eutral ferrocene is hydrophobic and insoluble in water owing to the presence of two hydrophobic cyclopentadienylr ings, which can form as tronger hydrogel.…”