Single-molecule observation of long jumps in polymer adsorption

Changqian Yu, Juan Guan, Kejia Chen, Sung Chul Bae, Steve Granick

Research output: Contribution to journalArticlepeer-review


Single-molecule fluorescence imaging of adsorption onto initially bare surfaces shows that polymer chains need not localize immediately after arrival. In a system optimized to present limited adsorption sites (quartz surface to which polyethylene glycol (PEG) chains adsorb from aqueous solution at pH 8.2), we find that some chains diffuse back into bulk solution and readsorb at some distance away, sometimes multiple times before they either localize at a stable position or diffuse away into bulk solution. This mechanism of surface diffusion is considerably more rapid than the classical model in which adsorbed polymers crawl on surfaces while the entire molecule remains adsorbed, suggesting the conceptual generality of a recent report (Phys. Rev. Lett. 2013, 110, 256101) but in a new experimental system and with comparison of different chain lengths. We find the trajectories with jumps to follow a truncated Lévy distribution of step size with limiting slope-2.5, consistent with a well-defined, rapid surface diffusion coefficient over the times we observe. The broad waiting time distribution appears to reflect that polymer chains possess a broad distribution of bound fraction: the smaller the bound fraction of a given chain, the shorter the surface residence time before executing the next surface jump.

Original languageEnglish (US)
Pages (from-to)9735-9742
Number of pages8
JournalACS Nano
Issue number11
StatePublished - Nov 26 2013
Externally publishedYes


  • jump
  • polymer adsorption/desorption
  • single-molecule fluorescence imaging
  • surface diffusion
  • truncated Lévy distribution

ASJC Scopus subject areas

  • Engineering(all)
  • Materials Science(all)
  • Physics and Astronomy(all)


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