title: Differential self-assembly and tunable emission of aromatic peptide bola-amphiphiles containing perylene bisimide in polar solvents including water.
abstract: We demonstrate the self-assembly of bola-amphiphile-type conjugates of dipeptides and perylene bisimide (PBI) in water and other polar solvents. Depending on the nature of the peptide used (glycine-tyrosine, GY, or glycine-aspartic acid, GD), the balance between H-bonding and aromatic stacking can be tailored. In aqueous buffer, PBI-[GY]2 forms chiral nanofibers, resulting in the formation of a hydrogel, while for PBI-[GD]2 achiral spherical aggregates are formed, demonstrating that the peptide sequence has a profound effect on the structure formed. In water and a range of other polar solvents, self-assembly of these two PBI-peptides conjugates results in different nanostructures with highly tunable fluorescence performance depending on the peptide sequence employed, e.g., fluorescent emission and quantum yield. Organogels are formed for the PBI-[GD]2 derivative in DMF and DMSO while PBI-[GY]2 gels in DMF. To the best of our knowledge, this is the first successful strategy for using short peptides, specifically, their sequence/structure relationships, to manipulate the PBI nanostructure and consequent optical properties. The combination of controlled self-assembly, varied optical properties, and formation of aqueous and organic gel-phase materials may facilitate the design of devices for various applications related to light harvesting and sensing.
authors.affiliation: WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde , Glasgow G1 1XL, U.K.
authors.forename: Shuo
authors.initials: S
authors.lastname: Bai
authors.forename: Sisir
authors.initials: S
authors.lastname: Debnath
authors.forename: Nadeem
authors.initials: N
authors.lastname: Javid
authors.forename: Pim W J M
authors.initials: PW
authors.lastname: Frederix
authors.forename: Scott
authors.initials: S
authors.lastname: Fleming
authors.forename: Charalampos
authors.initials: C
authors.lastname: Pappas
authors.forename: Rein V
authors.initials: RV
authors.lastname: Ulijn
mesh_terms: D007094:Imides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D007094:Imides; D010455:Peptides; D012997:Solvents; C510697:perylene bisimide; D014867:Water; D010569:Perylene