Available Technology
High-sensitivity chiral molecule detection technique using tiny samples
Technology:
Light beam splitting effect
Markets Addressed
Light normally behaves in a very predictable way. The law of reflection says that a wave of particles is reflected off a boundary at an angle equal to the angle at which it hit the boundary; but is it always? Researchers at Harvard have shown for the first time that light reflected off the surface of a chiral liquid not only bounces back at a different angle, but is also split in two. Typically, one needs to detect small concentrations of chiral molecules, and so detections of deflections down to a few nanoradians is needed. The beam splitting effect could be used by analytical chemists in drug research and development to sensitively analyze the chirality of unknown substances using only a tiny sample.
Innovations and Advantages
The significance of this optical effect is that it permits detection of chiral molecules in nanoliters, rather than the large sample-volumes that are currently needed in laboratory polarimeters. For the last 200 years, chiral molecules have been detected in polarimeters by observing the rotation of a plane polarized light beam that traverses an “optically active” liquid. However, this requires long path-lengths and large sample-volumes, whereas “light-splitting” occurs within a micron at an interface and can be observed in minute volumes. Using position sensitive detection (PSD) and polarization modulators we can routinely measure angular deflections of around 50 nanoradians.
Additional Information
Intellectual Property Status: Issued U.S. patent nos.: 7,961,318
Research:
The Rowland Institute - Splitting light in a chiral medium
Publications:
A. Ghosh and P. Fischer, “Chiral Molecules Split Light: Reflection and Refraction in a Chiral Liquid”, Phys. Rev. Lett., 97, (2006), 173002 Link to the article
A. Ghosh, F.M. Fazal, and P. Fischer, “Circular differential double diffraction in chiral media”, Opt. Lett., 32, (2007), 1836 Link to the article
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Inventor(s):
Fischer, Peer
Ghosh, Ambarish
Categories:
For further information, please contact:
Alan Gordon, Director of Business Development
(617) 384-5000
Reference Harvard Case #2752