Now showing 1 - 3 of 3
  • Publication
    Thermal and aqueous stability improvement of graphene oxide enhanced diphenylalanine nanocomposites
    Nanocomposites of diphenylalanine (FF) and carbon based materials provide an opportunity to overcome drawbacks associated with using FF micro- and nanostructures in nanobiotechnology applications, in particular, their poor structural stability in liquid solutions. In this study, FF/graphene oxide (GO) composites were found to self-assemble into layered micro- and nanostructures, which exhibited improved thermal and aqueous stability. Dependent on the FF/GO ratio, the solubility of these structures was reduced to 35.65% after 30 min as compared to 92.4% for pure FF samples. Such functional nanocomposites may extend the use of FF structures to, e.g., biosensing, electrochemical, electromechanical or electronic applications.
  • Publication
    Wettability gradient-induced alignment of peptide nanotubes as templates for biosensing applications
    Self-assembled diphenylalanine (FF) peptide nanotubes (PNTs) have attracted significant attention due to their well-ordered supramolecular structure and wide range of functional capabilities that may enable potential nanobiotechnology applications. However, self-assembled PNTs are generally inhomogeneous at the macroscale, which has limited their potential use. Reproducibly controlling the assembly and alignment of PNTs is therefore critical to enable the widespread use of PNTs, e.g., in sensing applications. In this study, a surface patterning technique based on UV/ozone exposure through a mask is used to align PNTs. Exposed regions become hydrophilic, leading to directed spreading of the FF solution and alignment of the PNTs that improves as the difference in wettability between adjacent regions increases. Alignment was further found to depend on the concentration- and temperature-dependent diameter of the PNTs formed and the size of the hydrophilic area. Finally, aligned PNTs decorated with silver nanoparticles are used to sense an analyte molecule using surface enhanced Raman spectroscopy.
      266Scopus© Citations 29
  • Publication
    Nanoscale Piezoelectric Properties of Self-Assembled Fmoc-FF Peptide Fibrous Networks
    Fibrous peptide networks, such as the structural framework of self-assembled fluorenylmethyloxycarbonyl diphenylalanine (Fmoc-FF) nanofibrils, have mechanical properties that could successfully mimic natural tissues, making them promising materials for tissue engineering scaffolds. These nanomaterials have been determined to exhibit shear piezoelectricity using piezoresponse force microscopy, as previously reported for FF nanotubes. Structural analyses of Fmoc-FF nanofibrils suggest that the observed piezoelectric response may result from the noncentrosymmetric nature of an underlying β-sheet topology. The observed piezoelectricity of Fmoc-FF fibrous networks is advantageous for a range of biomedical applications where electrical or mechanical stimuli are required.
      356Scopus© Citations 50