Research

Why “single-molecule”?

  • Remove ensemble averaging to characterize individual molecules in the heterogeneous system

  • Monitor rare events overwhelmed by several parallel pathways occurs at the same time

  • Achieve precise molecular control and explore tremendous structural details at the most fundamental level

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☘ Remove ensemble averaging to characterize individual molecules in the heterogeneous system

☘ Monitor rare events overwhelmed by several parallel pathways occurs at the same time

☘ Achieve precise molecular control and explore tremendous structural details at the most fundamental level



Our Method

Experimental platform for single-molecule optical manipulation and spectroscopic characterization

Learn more about the Nobel Prize-winning technologies -- optical tweezers: Tools made of light at:

https://www.nobelprize.org/prizes/physics/2018/popular-information/

and Raman spectroscopy: The molecular scattering of light at:

https://www.nobelprize.org/uploads/2018/06/raman-lecture.pdf

  • Single-molecule surface-enhanced Raman spectroscopy (smSERS)

  • Optical tweezers based single-molecule force spectroscopy (SMFS)

  • Single-molecule force coupled Raman spectroscopy (smFoRS)



♠ Single-molecule surface-enhanced Raman spectroscopy (smSERS)

Reference:

Nie, S.; Emory, S. R. Probing single molecules and single nanoparticles by surface-enhanced Raman scattering. Science 1997, 275, 1102

Kneipp, K.; Wang, Y.; Kneipp, H.; Perelman, L. T.; Itzkan, I.; Dasari, R. R.; Feld, M. S. Single molecule detection using surface-enhanced Raman scattering (SERS). Physical Review Letters 1997, 78(9), 1667

♠ Optical tweezers based single-molecule force spectroscopy (SMFS)

Reference:

Ashkin, A. Optical trapping and manipulation of neutral particles using lasers. Proceedings of the National Academy of Sciences 1997, 94, 4853

Cecconi, C.; Shank, E. A.; Bustamante, C.; Marqusee, S. Direct Observation of the three-state folding of a single protein molecule. Science 2005, 309, 2057

♠ Single-molecule force coupled Raman spectroscopy (smFoRS)

We are integrating surface-enhanced Raman spectroscopy and optical tweezers based single-molecule force spectroscopy to construct single-molecule Force-coupled Raman Spectroscopy (smFRS), which brings in a new dimension of information to depict molecular vibrations for the structural characterization in a label-free manner, while still delineates the individual molecular behavior with precise force manipulations.

Topics of Interests

⚡Investigating Molecular Mechanisms of Protein Folding, Misfolding and Aggregation

⚡Controlling and Characterizing Biological Macromolecules and Biomaterials

⚡Big Data Analysis in Biophysical Chemistry