title: A bolaamphiphilic amino acid appended photo-switching supramolecular gel and tuning of photo-switching behaviour.
abstract: 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.
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032, India. bcab@iacs.res.in.
authors.forename: Subhasish
authors.initials: S
authors.lastname: Roy
authors.forename: Dibakar Kumar
authors.initials: DK
authors.lastname: Maiti
authors.forename: Shrabani
authors.initials: S
authors.lastname: Panigrahi
authors.forename: Durga
authors.initials: D
authors.lastname: Basak
authors.forename: Arindam
authors.initials: A
authors.lastname: Banerjee
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D005663:Furans / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007094:Imides / Q000737:chemistry; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D010087:Oxides / Q000737:chemistry; D010569:Perylene / Q000031:analogs & derivatives / Q000737:chemistry; D011728:Pyridones / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000596:Amino Acids; D005663:Furans; D007094:Imides; D010087:Oxides; D011728:Pyridones; C543575:bolaamphiphile; C510697:perylene bisimide; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D010569:Perylene; D006108:Graphite