Molecule–surface
collisions are known to initiate dynamics
that lead to products inaccessible by thermal chemistry. These collision
dynamics, however, have mostly been examined on bulk surfaces, leaving
vast opportunities unexplored for molecular collisions on nanostructures,
especially on those that exhibit mechanical properties radically different
from those of their bulk counterparts. Probing energy-dependent dynamics
on nanostructures, particularly for large molecules, has been challenging
due to their fast time scales and high structural complexity. Here,
by examining the dynamics of a protein impinging on a freestanding,
single-atom-thick membrane, we discover molecule-on-trampoline dynamics that disperse the collision impact away from the incident
protein within a few picoseconds. As a result, our experiments and ab initio calculations show that cytochrome c retains its
gas-phase folded structure when it collides onto freestanding single-layer
graphene at low energies (∼20 meV/atom). The molecule-on-trampoline dynamics, expected to be operative on many freestanding atomic membranes,
enable reliable means to transfer gas-phase macromolecular structures
onto freestanding surfaces for their single-molecule imaging, complementing
many bioanalytical techniques