Force Spectroscopy of Quadruple H-Bonded Dimers by AFM:Dynamic Bond Rupture and Molecular Time-Temperature Superposition

摘要

Noncovalent molecular interactions govern the formation of well-defined,hierarchical(supra)molecular architectures in spontaneous self-assembly processes.The strength of these molecular interactions has traditionally been assessed by ensemble thermodynamics.However,with the growing interest in molecular level biochemistry and-physics,as well as molecular nanotechnology,there is an increasing need for knowledge regarding molecular stability and bond strengths from the single-molecule perspective,i.e.,without ensemble averaging.Atomic force microscopy(AFM)allows one to obtain data on bond rupture and molecular force-stretching behavior of biological and synthetic macromolecules in single-molecule force spectroscopy(SMFS)5 measurements.In these experiments the imaging media(solvents)and temperature as well as the linkage stiffness(cantilever spring constant,polymer spacer)and loading rates can,in principle,be varied.