Optical Tweezers: from Biophysics to Chemical Physics.

Optical Tweezers have resulted in transformative mechanistic understanding of biological processes by allowing unambiguous and reproducible measurements on single molecules. Using this technique, we can trap and isolate a single molecule away from surface heterogeneities and manipulate it with nanometer resolution and piconewton control. The application of this powerful technique to solution-phase chemistry and materials characterization has been hampered by the inability to achieve stable trapping in organic solvents. Here, I present our recent advances in extending optical tweezers to experiments on single molecules in a variety of solvents. Furthermore, I report on our preliminary measurements of optically-induced forces and demonstrate that force-detected absorption spectroscopy allows for nanoscale mapping of absorption profiles.