Macroscopic Alignment and Assembly of pi-Conjugated Oligopeptides Using Colloidal Microchannels

作者：Li Bo; Valverde Lawrence R; Zhang Fengjiao; Zhou Yuecheng; Li Songsong; Diao Ying; Wilson William L; Schroeder Charles M^*

来源：ACS Applied Materials & Interfaces, 2017, 9(47): 41586-41593.

DOI：10.1021/acsami.7b13978

• pi-conjugated oligopeptides
• colloidal microchannels
• self-assembly
• atomic force microscope-infrared spectroscopy (AFM-IR)
• photoinduced force microscopy (PiFM)

One-dimensional (1-D) supramolecular self-assembly offers a powerful strategy to achieve long-range unidirectional ordering of organic semiconducting materials via noncovalent interactions. Using a hierarchical assembly, electronic and optoelectronic materials can be constructed for applications including organic conducting nanowires, organic fieldeffect transistors (OFETs), and organic light-emitting devices (OLEDs). Despite recent progress, it remains challenging to precisely align and assemble 1-D structures over large areas in a rapid and straightforward manner. In this work, we demonstrate a facile strategy to macroscopically align supramolecular fibers using a templating method based on sacrificial colloidal microchannels. Through use of this approach, colloidal microchannels are generated on a solid surface using a simple fabrication method, followed by the spontaneous self-assembly of pi-conjugated oligopeptides inside large arrays of microchannels triggered by solvent evaporation. Following oligopeptide assembly and removal of sacrificial microchannels, the structural properties of oligopeptide fibers were characterized using atomic force microscopy (AFM), atomic force microscope-infrared spectroscopy (AFM-IR), photoinduced force microscopy (PiFM), fluorescence polarization microscopy, and electron microscopy. These results reveal the macroscopic alignment of oligopeptide fibers into ordered structures over millimeter length scales, facilitated by colloidal microchannel templating. In addition, the charge transport properties (I-V curves) of pi-conjugated oligopeptides assembled using this method were determined under a wide range of applied voltages using interdigitated array electrodes and conductive AFM. Overall, this work illustrates a simple yet robust strategy to pattern 1-D supramolecular fibers over large areas, thereby offering new routes for assembling materials for organic electronics.

• 出版日期2017-11-29