Harvard College

Gottfried Wilhelm Leibniz Universitat Hannover

Eric Diebold

Eric Mazur

Steven M Ebstein

Alexander Heisterkamp

The invention provides methods and systems for separating particles that exhibit different Raman characteristics. The method can include introducing nanoparticles, on which Raman-active molecules are adsorbed, into a photopolymerizable resin and exposing to excite Raman active vibrational modes of the molecules to generate Raman-shifted radiation suitable for polymerizing the resin such that the Raman-shifted radiation causes selective polymerization of a resin surrounding nanoparticles if the nanoparticles provide a Raman enhancement factor greater than a threshold. In addition, methods for electrically isolating nanoparticles, or selectively removing one type of nanoparticles from collections, are disclosed. These methods rely on generation of blue-shifted anti-Stokes photons to selectively expose portions of a photoresist covering the nanoparticles to those photons. Such exposure can cause a change in the exposed portions (e.g., polymerize or increase solubility to a developing agent), which can be employed to achieve isolation of the nanoparticles or their selective removal.

Nanoparticle separation using coherent anti-stokes Raman scattering

In one aspect, a system for use in product packaging is disclosed that includes a polymeric sensing substrate coupled to a package such that a front sensing surface thereof is in contact with a portion of a product, e.g., a fungible product, stored in the package and a back surface thereof is accessible via an environment external to the package. The system further includes a radiation source adapted to direct radiation to the substrate's back surface such that the radiation would interact with one or more molecular species of the product that are in contact with the substrate's sensing surface. The system also includes a detector that is adapted to detect radiation returning from the substrate in response to its illumination by the radiation source. The front surface of the sensing substrate can comprise a plurality of micron-sized or submicron-sized ridges having a discontinuous or continuous metal coating, e.g., a metallic layer with a thickness in a range of about 10 nm to about 1000 nm (and preferably in a range of about 50 nm to about 120 nm), disposed thereon.

Non-invasive optical analysis using surface enhanced raman spectroscopy

In one aspect, the present invention provides methods for fabricating substrates for use in a variety of analytical and/or diagnostic applications. Such a substrate can be generated by exposing a semiconductor surface (e.g., silicon surface) to a plurality of short laser pulses to generate micron-sized, and preferably submicron-sized, structures on the surface. The structured surface can then be coated with discontinuous metal coating characterized by one or more metalized surface region and a plurality of surface gaps.

Substrates for Raman spectroscopy having discontinuous metal coatings

In one aspect, the present invention generally provides methods for fabricating substrates for use in a variety of analytical and/or diagnostic applications. Such a substrate can be generated by exposing a semiconductor surface (e.g., silicon surface) to a plurality of short laser pulses to generate micron-sized, and preferably submicron-sized, structures on the surface. The structured surface can then be coated with a thin metallic layer, e.g., one having a thickness in a range of about 10 nm to about 1000 nm.

Growing community of inventors

Boston, MA, United States of America

Eric Diebold