Single-molecule diffusion in a periodic potential at a solid-liquid interface.
We used single-molecule tracking experiments to observe the motion of small hydrophobic fluorescent molecules at the interface between water and a solid surface that exhibited periodic chemical patterns. The dynamics were characterized by non-ergodic, continuous time random walk statistics. The step-size distributions displayed enhanced probability of steps to periodic distances, consistent with theoretical predictions for diffusion in an atomic/molecular scale periodic potential. Surprisingly, this general behavior was observed here for surfaces exhibiting characteristic length scales three orders of magnitude larger than atomic/molecular dimensions, and may provide a new way to understand and control solid-liquid interfacial diffusion for molecular targeting applications.
Department of Chemical and Biological Engineering, University of Colorado Boulder, Boulder, CO 80309, USA. daniel.schwartz@colorado.edu.
Michael J
MJ
Skaug
Anna M
AM
Lacasta
Laureano
L
Ramirez-Piscina
Jose M
JM
Sancho
Katja
K
Lindenberg
Daniel K
DK
Schwartz