RESUMO
Self-assembled bolaamphiphilic perylene bisimide (PBI) containing an amino acid appended fluorescent semiconducting soft material (hydrogel) has been discovered at physiological pH. This new organic material based on self-assembled perylene bisimide appended amino acid-based bolaamphiphile (PBI-C11-Y) has been well characterized using various techniques including UV-Vis, fluorescence, X-ray diffraction, FT-IR, transmission electron microscopic (TEM) and atomic force microscopic (AFM) studies. Interestingly, the UV-Vis absorption properties of the soft-material are dependent on the pH of the medium. This PBI-conjugated amino acid appended gelator molecule contains a centrally located perylene bisimide moiety as well as an aromatic amino acid l-tyrosine at the side chains, which are extremely useful for interacting with the delocalized large π-surface of GO (graphene oxide) or RGO (reduced graphene oxide) to form a GO/RGO containing hybrid hydrogel. Graphene oxide and reduced graphene oxide have been successfully incorporated into the nanofibrillar network structure of the PBI-C11-Y based gel to make nanohybrid systems. The I-V profile of the semiconducting photo-responsive soft-material of the PBI-C11-Y has been successfully tuned upon the incorporation of GO and RGO within the gel-based soft material. This PBI-C11-Y xerogel based structure shows photo-switching behaviour upon exposure to white light. The ON/OFF ratio of the PBI-C11-Y can be modulated upon the inclusion of GO and RGO within the hydrogel matrix. Furthermore, the OFF state stability of the PBI-C11-Y xerogel material has been increased upon the inclusion of RGO. Regulation of the photo-switching behaviour of the PBI-C11-Y based xerogel holds promise for making PBI-containing amino acid appended biomaterials with interesting properties in future.
Assuntos
Aminoácidos/química , Furanos/química , Hidrogel de Polietilenoglicol-Dimetacrilato/química , Piridonas/química , Grafite/química , Concentração de Íons de Hidrogênio , Imidas/química , Microscopia de Força Atômica , Microscopia Eletrônica de Transmissão , Óxidos/química , Perileno/análogos & derivados , Perileno/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
A peptide based two component white light emitting system has been designed and developed on the basis of a co-assembly of a PDI containing peptide system as an acceptor and a stilbene containing peptide system as a donor in organic solvents.
Assuntos
Luz , Peptídeos/química , Clorobenzenos/química , Transferência Ressonante de Energia de Fluorescência , Imidas/química , Estrutura Molecular , Perileno/análogos & derivados , Perileno/químicaRESUMO
A synthetic amino acid (with a stilbene residue in the main chain) containing a tripeptide-based organogelator has been discovered. This peptide-based synthetic molecule 1 self-assembles in various organic solvents to form an organogel. The gel has been thoroughly characterized by using various microscopic techniques including field-emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), X-ray diffraction (XRD), UV-visible and fluorescence spectroscopy, and rheology. Morphological investigations using FESEM and AFM show a nanofibrillar network structure. Interestingly, the organogel is photoresponsive and a gel-sol transition occurred by irradiating the gel with UV light of 365 nm for 2 h as shown by the UV and fluorescence study. This photoresponsive fluorescent gel holds promise for new peptide-based soft materials with interesting applications.
