The adsorption/desorption behavior of mobile solute molecules at a solution-crystal interface has been explored using crystals of model protein hen egg-white lysozyme (HEWL) and fluorescent-labeled HEWL (F-HEWL) molecules. We have tracked the transient processes occurring during adsorption/desorption of identical F-HEWL molecules on a tetragonal HEWL crystal surface by single-molecule visualization using a total internal reflection fluorescent microscope and pulsed discontinuous laser illumination. We found an induction period (similar to 70 min) after which the number density of F-HEWL molecules adsorbed mainly on steps increased linearly with the adsorption time. We show direct evidence that the residence time of molecules on the crystal surface gradually increases during the transition process from a solute species to the crystal after successive multistep processes.
This paper was published as:
Dai GL; Sazaki G; Matsui T; Tsukamoto K; Nakajima K; Kang Q; Hu WR. Gradual Immobilization Processes of Molecules during Transitions from Solute to Solid States. CRYSTAL GROWTH & DESIGN, 11(1):88-92(2011)