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SERS Identification of Optically Trapped Molecule

The US Army has developed a new analytical method, based upon simultaneous exploitation of optical trapping and surface-enhanced Raman scattering (SERS) phenomena, sensitive enough to make positive identification of a suspected threat agent using only a single particle.  This patented invention represents the first use of these technologies in combination, with the resultant characterization accomplished in just minutes, instead of the hours or days needed using traditional methods.
Particles suitable for characterization include eukaryotic cells, bacteria, viruses, polymer strands, organelles, colloids, antibodies, ribosomes, nanocrystals, each alone or adhered as an aggregate particle.   

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New ability to characterize a single particle in a non-destructive manner
New ability to characterize a single particle in a non-destructive manner
The Technology: 

The US Army Research Laboratory (ARL) is a nationally-recognized innovator of diagnostic biotechnologies and is currently focused on rapid characterization of potential biothreats.  
The invented ARL system is comprised of a laser operating in the visible to near-infrared wavelength (approx. 650 to 1100 nanometers).  The beam provides attractive and repulsive forces that can physically move and hold dielectric particles in a fashion akin to tweezers.  This optical trap is proximal to a set up that enables analysis by SERS, where a generated surface-plasmon-resonance electric field yields a scattering spectrum unique to a subject particle.  The spectrum is background-corrected and then compared with published data via an automated chemometric system.  
The ARL invention is practiced using commercial-off-the shelf components and supplies.  The system is non-invasive and non-destructive, does not suffer interference from water and is insensitive to the excitation wavelength.  The patent includes a method of particle detection analysis and an approach for building a library of enhanced particle scattering spectra. Other patents related to portable acoustic spectroscopy are available for license as well.

Benefits: 
  • Unique capability to characterize single particles with averaged linear dimension between 0.10 and 50 microns 
  • Reduces analysis time to minutes, instead of hours or days needed with traditional methods
  • Commercial-off-the-shelf components apability to analyze single, dielectric particles with averaged linear dimension between 0.10 and 50 microns 
  • Broad applicability to military, medical, food preparation, homeland security, law enforcement
The Opportunity: 
  • Issued patent US 7,515,269
  • TRL 5 – Fully-developed detection system, with data available 
  • Potential for collaboration with US Army scientists and laboratory
Contacts: