University of Pittsburgh

Sandy Asher

Contact Info:

Department of Chemistry
Chevron Science Center
219 Parkman Avenue
Pittsburgh, PA 15260

Office: 701 CHVRN
Phone: 412-624-8570

Distinguished Professor

Analytical Chemistry, Biophysical Chemistry, Materials Science and Physical Chemistry

Professor Asher's research program is interdisciplinary and brings together scientists in analytical chemistry, biophysical chemistry, materials science and physical chemistry to solve important scientific and technological problems. The research has both
fundamental and applied aspects. The most fundamental research involves calculations of the interactions between light and matter, and the examination of excited states of molecules. Applied work includes the spectroscopic investigation of protein structure and function, and development of a chemical understanding of the gas phase and solid phase reactions occurring during synthesis of diamond in CVD diamond reactors. Another example is the fabrication of new "smart" materials for use in novel optical devices, sensors, and for use in optical computers. Examples of research projects underway include:

Amide Excited States and Proteins Folding

The Asher group has pioneered the development of UV Raman spectroscopy to study molecular structure. UV excitation with novel laser sources, allows us to study interactions between the molecular electron cloud and nuclear vibrations. This gives us incisive glimpses into molecular structure.

We have developed a new methodology for structure characterization of proteins using UV resonance Raman spectroscopy. For the first time, we have applied nanosecond time-resolved UVRR spectroscopy for kinetic studies of protein folding. Rapid laser-induced temperature jumps are used to initiate the folding process; transient vibrational spectra are recorded using time-delayed probe pulses to characterize of the intermediate states involved (Fig. 1).

Diamond Growth Chemistry

We have constructed a UV Raman instrument on a CVD diamond reactor at Westinghouse Corp. and are developing an in situ spectroscopic method to monitor the diamond growth and the gas phase chemistry, in order to optimize the growth conditions. This project represents a unique partnership between academia and industry.

Materials Science and Non Linear Optics

We have developed novel materials based on crystalline colloidal (CCA) self assembly. CCA are ordered arrays of colloidal particles formed in a liquid. The colloidal particles repel each other and form a cubic array which Bragg diffracts light from the UV through the visible and the IR spectral region. These arrays serve as diffracting optical devices. We have developed methods to polymerize these arrays in solid films that change dimension in response to chemical, electrical, and thermal environmental changes (Fig. 2). We have utilized these materials to develop a new chemical sensing motif which creates a new generation of optical switches for use in optical computing, for chemical separations and for thin film display devices.

Awards

  • 2015 FACSS Charles Mann Award for Applied Raman Spectroscopy

  • Scientific Advisor, Taiwan Association of Raman Spectroscopy, 2013

  • Charles E. Kaufman Award, 2011

  • Member, University of Pittsburgh Research Council, 2009

  • Spectroscopy Society of Pittsburgh, Pittsburgh Spectroscopy Award, 2008

  • Society Fellow, Society for Applied Spectroscopy, 2007

  • Distinguished Professor of Chemistry, University of Pittsburgh, 2006

  • Sigi Ziering Award for Outstanding Contribution of a Publication in the Journal, Clinical Chemistry, 2005

  • University of Missouri-St. Louis Distinguished Alumnus Award, 2004

  • ACS Pittsburgh Award, 2002

  • Ellis R. Lippincott Award, 2002

  • Pittsburgh Technology Council EnterPrize Award, 2000

  • Bomen-Michelson Award, 1999

  • Lester W. Strock Award, 1998

  • University of Pittsburgh Chancellor's Distinguished Research Award, 1996

  • ACS Analytical Division Spectrochemical Analysis Award, 1994

  • Distinguished Alumni Award of the University of Missouri, 1988

  • American Heart Association Established Investigator Award

Publications

SHERLOC: Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals, an Investigation for 2020,” L.W. Beegle, R. Bhartia, L. DeFlores, M. Darrach, R.D. Kidd, W. Abbey, S. Asher, A. Burton, S. Clegg, P.G. Conrad, K. Edgett, B. Ehlmann, F. Langenhorst, M. Fries, W. Hug, K. Nealson, J. Popp, P. Sorbon, A. Steele, R. Wiens, K. Williford, Proceedings of 45th Lunar and Planetary Science Conference, March 17-21 2014., Pages 2835,
2D Photonic Crystal Protein Hydrogel Coulometer for Sensing Serum Albumin Ligand Binding,” Z. Cai, J.-T. Zhang, F. Xue, Z. Hong, D. Punihaole and S.A. Asher, Analytical Chemistry, Vol. 86, 2014, Pages 4840-4847,
Solution and Solid Trinitrotoluene (TNT) Photochemistry: Persistence of TNT-like Ultraviolet (UV) Resonance Raman Bands,” K.L. Gares, S.V. Bykov, B. Godugu and S.A. Asher, Applied Spectroscopy, Vol. 68, 2014, Pages 49-56,
Asymmetric Free-Standing 2-D Photonic Crystal Films and their Janus Particles,” J.T. Zhang, X. Chao and S.A. Asher, Journal of the American Chemical Society, Vol. 135, 2013, Pages 11397-11401,
Vertical Spreading of Two-Dimensional Crystalline Colloidal Arrays,” J.T. Zhang, L. Wang, X. Chao, S.S. Velankar and S.A. Asher, Journal of Materials Chemistry C, Vol. 1, 2013, Pages 6099-6102,
High-Throughput, High-Resolution Echelle Deep-UV Raman Spectrometer,” S.V. Bykov, B. Sharma and S.A. Asher, Applied Spectroscopy, Vol. 67, 2013, Pages 873-883,
Two-Dimensional Array Debye Ring Diffraction Protein Recognition Sensing,” J.T. Zhang, X. Chao, X. Liu and S.A. Asher, Chem. Commun., Vol. 49, 2013, Pages 6337-6339,
UV Resonance Raman and DFT Studies of Arginine Side Chains in Peptides: Insights into Arginine Hydration,” Z. Hong, J. Wert and S.A. Asher, Journal of Physical Chemistry B, Vol. 117, 2013, Pages 7145-7156,
Langevin Dynamics Simulation of 3D Colloidal Crystal Vacancies and Phase Transitions,” R. Laghaei, S.A. Asher and R.D. Coalson, Journal of Physical Chemistry B, Vol. 117, 2013, Pages 5271-5279,
Insight into Resolution Enhancement in Generalized Two-Dimensional Correlation Spectroscopy,” L. Ma, V. Sikirzhytski, Z. Hong, I.K. Lednev, S.A. Asher, Applied Spectroscopy, Vol. 67, 2013, Pages 283-290,
Resonance Raman Spectra of TNT and RDX using Vibronic Theory, Excited-State Gradient and Complex Polarizability Approximations,” W.A. Al-Saidi, S.A. Asher and P. Norman, Journal of Physical Chemistry A, Vol. 116, 2012, Pages 7862-7872,
Two-Dimensional Photonic Crystals Surfactant Detection,” J. Zhang, N. Smith and S.A. Asher, Analytical Chemistry, Vol. 84, 2012, Pages 6416-6420,
UV Resonance Raman Spectroscopy Monitors Polyglutamine Backbone and Side Chain Hydrogen Bonding and Fibrillization,” K. Xiong, D. Punihaole and S.A. Asher, Biochemistry, Vol. 51, 2012, Pages 5822-5830,
Impact of Ion Binding on Poly-L-Lysine (Un)folding Energy Landscape and Kinetics,” K. Xiong and S.A. Asher, Journal of Physical Chemistry B, Vol. 116, 2012, Pages 7102-7112,
Deep UV Resonance Raman Excitation Profiles of NH4NO3, PETN, TNT, HMX and RDX,” M. Ghosh, L. Wang and S.A. Asher, Applied Spectroscopy, Vol. 66, 2012, Pages 1013-1021,
Fabrication of Large-Area Two-Dimensional Colloidal Crystals,” J.T. Zhang, L. Wang, D.N. Lamont, S. Velankar and S.A. Asher, Angew. Chem. Int. Ed., Vol. 51, 2012, Pages 6117-6120,
Reflectivity Enhanced Two-Dimensional Dielectric Particle Array Monolayer Diffraction,” A. Tikhonov, N. Kornienko, J. Zhang, L. Wang and S.A. Asher, Journal of Nanophotonics, Vol. 6, 2012, Pages 063509-1 - 063509-9,
UV Resonance Raman Investigations of Peptide and Protein Structure and Dynamics,” S.A. Oladepo, K. Xiong, Z. Hong, S.A. Asher, J. Handen and I.K. Lednev, Chemical Reviews, Vol. 112, 2012, Pages 2604-2628,
Silica Crystalline Colloidal Array Deep Ultraviolet Narrow-Band Diffraction Devices,” L. Wang, A. Tikhonov and S.A. Asher, Applied Spectroscopy, Vol. 66, 2012, Pages 426-431.,
UV Resonance Raman Studies of the NaClO4 Dependence of the Poly-L-Lysine Conformation and Hydrogen Exchange Kinetics,” L. Ma, Z. Hong, B. Sharma and S.A. Asher, J. Phys. Chem. B., Vol. 116, 2012, Pages 1134-1142.,