Measuring dipole moment of single protein molecules

from the just-a-moment dept.
Researchers have devised a method to determine the alignment of a molecule's axis, the "poles" that govern how a molecule will interact with others. The advancement will help scientists and engineers predict the ways that atoms and molecules exchange energy, possibly enhancing solar energy devices or helping biochemists better understand proteins. The research, appearing in the 4 June 2001 issue of Physical Review Letters, shows how a tightly-focused laser employing a new kind of polarization can produce valuable images of individual molecules in three dimensions.
The new method takes a snapshot of a phenomenon called the "molecular dipole moment." This "moment" is an axis that runs through the molecule like a north and south pole, along which energy is emitted and absorbed. If two molecules are positioned so that their respective poles align, they are more likely to exchange energy. If they are completely misaligned, then an interaction is more difficult. The researchers hope the work may lead to control of the alignment to direct chemical reactions at the atomic level.