Probing Single Molecule Binding and Free Energy Profile with Plasmonic Imaging of Nanoparticles

Hui Wang, Zhuodong Tang, Yan Wang, Guangzhong Ma, Nongjian Tao

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


Measuring binding between molecules is critical for understanding basic biochemical processes, developing molecular diagnosis, and screening drugs. Here we study molecular binding at the single molecule level by attaching nanoparticles to the molecular binding pairs. We track the thermal fluctuations of the individual nanoparticles with sub-nanometer precision using a plasmonic scattering imaging technique and show that the fluctuations are controlled by the molecular binding pairs rather than by the nanoparticles. Analysis of the thermal fluctuations provides unique information on molecular binding, including binding energy profile, effective spring constant, and switching between single and multiple molecular binding events. The method provides new insights into molecular binding and also allows one to differentiate nonspecific binding from specific binding, which has been a difficult task in biosensors.

Original languageEnglish (US)
Pages (from-to)16071-16078
Number of pages8
JournalJournal of the American Chemical Society
Issue number40
StatePublished - Oct 9 2019

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry


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