C–H Stretch for Probing Kinetics of Self-Assembly into Macromolecular Chiral Structures at Interfaces by Chiral Sum Frequency Generation Spectroscopy

• DOI: 10.1021/la304954h
• Publication Date: 2013-03-04T19:47:05Z
• Authors: Zhuguang Wang; Li Fu; Elsa C. Y. Yan
• Keywords: Surface Properties; Air; Spectrum Analysis; Water; Stereoisomerism; Hydrogen-Ion Concentration; Vibration; 01 natural sciences; Protein Structure, Secondary; 0104 chemical sciences; Kinetics; Surface-Active Agents; Adsorption; Peptides

Self-assembly of molecules into chiral macromolecular and supramolecular structures at interfaces is important in various fields, such as biomedicine, polymer sciences, material chemistry. However, probing the kinetics remains challenging because it requires a real-time method that has selectivity to both interface chirality. Here, we introduce an situ approach using C-H stretch vibrational probe detected by sum frequency generation spectroscopy (cSFG). We showed cSFG signals amphiphilic peptide (LK7β) can reveal its self-assembly β-sheet air-water interface. The experiments conjunction with measurements surface pressure allow us propose mechanism process, which involves immediate adsorption disordered followed lag phase before antiparallel structures. Our implies general application study bioactive, simple organic, polymeric interfaces, will be useful tackling problems, protein aggregation, rational design functional materials, fabrication molecular devices.