Single-molecule force spectroscopy by AFM (AFM-SMFS) is an experimental methodology that allows unequivocal sensitivity and control for investigating and manipulating the mechanical properties of single molecules.
Functionalizing the AFM stylus with an appropriate linker-system tethering the ligand and optimizing the AFM conditions allows for imaging the engineered bacteriorhodopsin at subnanometer resolution while structurally mapping the specific ligand-receptor binding events.