Research Description

In the Schultz Lab, we believe the new scientific breakthroughs will be enabled by state of the art chemical measurement. Our research focuses on developing new tools for identifying molecules relevant to biomedical diagnostics and other applications.  To do this, we build and develop instrumentation that takes advantage of chemical properties to characterize complex samples.  The interaction between lasers and molecules provides unique information for detecting and identifying the components in complex systems.  Understanding the basic science involved in chemical detection and manipulating these interactions has led to breakthrough technologies with tremendous potential.  Much of the work in our lab involves vibrational spectroscopy, and in particular, Raman spectroscopy.  We commonly leverage nanoparticles to enhance the signal, an effect commonly referred to as surface enhanced Raman scattering (SERS).

Raman Imaging

The chemical specific Raman signal arising from the unique structure of molecules enables us to image chemical changes on the micrometer length scale.  We have used Raman imaging to explore chemical uptake in live cells as well as monitor chemical changes in samples.  In particular, our lab is interested in developing Raman imaging technology to increase spatial resolution, chemical information, monitor dynamic processes.

• Super Resolution SERS Spectral Imaging.  Fluctuations in the SERS signal from nanoparticles enable localization microscopy to be applied to SERS imaging, providing spatial resolution of a few nanometers.  We have developed spectral SERS imaging that provides both the position and chemical spectrum.  We are applying this technology to understand fundamental interactions between molecules and nanostructures as well as improve spatial resolution and sensitivity in live cell imaging experiments.
• Multimodal Imaging.  Coupling the chemical signals from Raman scattering with other imaging methods can increase understanding of the spatial activity of molecules.  Techniques that we investigate in tandem with Raman include photothermal imaging, atomic force microscopy, second harmonic generation, and other nonlinear imaging modalities.

Chemical Detection in Flow

We are exploring the use of surface enhanced Raman detection with online chemical separations such as: capillary electrophoresis, liquid chromatography, and other sampling techniques. Advances in instrumentation will enable new chemically selective methods for monitoring biological and other samples.  Our lab invented and is developing sheath-flow surface enhanced Raman scattering, which uses the unique pattern of scattered light associated with the structure of molecules, to improve molecular identification.  Applications include metabolomics and virus detection.

• Metabolomics: The ability to specifically identify and quantify the 40,000+ metabolites in the human body is essential for a systems biology approach to health care.  Changes in biochemical pathways can be distinguished provided enough intermediate molecules can be monitored accurately.  Current technologies can identify about 20% of the in biological samples.  Sheath-flow SERS is orthogonal to existing technologies and should extend coverage of the number of detectable metabolites.  In addition to identifying specific metabolites, the chemical rich signal can provide an indicator of metabolic phenotype.
• Virus Identification.  The unique molecules on the surface of viruses and other pathogens can be used to identify and quantify them.  We are exploring the chemical signatures on these samples to improve quantifying virus titer and identifying signatures of infectious species.