Session: Inorganic Spectroscopy:

Developing a mechanistic understanding of phenomena at the nano and single molecule scale is essential for advancing materials and nano technology. Optical tweezers (OT) have revolutionized the study of biology by enabling force measurements and manipulation of single molecules and complexes. I am interested in applying this technique to solution phase chemistry and to chemical characterization of materials at the single molecule level. An OT can manipulate and apply pico-newton forces to micron-sized dielectric particles and metallic nanoparticles held in a 3 dimensional trapping potential formed by a tightly focused laser beam. While our optical tweezer platform will measure force on particles, it has been custom designed to allow for simultaneous darkfield (DF) imaging of nanoparticles. Initial work was performed in water to show that gold nanoparticles could simultaneously be successfully imaged, trapped, and calibrated for force measurements on our instrument. Our current work is to fully move from work in water to trapping nanoparticles in nonpolar organic solvents for future chemical studies. Here I will discuss and show what effects the different environmental conditions, inherent to organic and aqueous solvents, have on the trapping and manipulation of gold nanoparticles. Further developing these techniques will allow us to measure the minute forces present during molecular absorption or conformational changes helping to characterize single molecules.

Daniel Jackson

PhD Student, Boston University

Appearances