Department of Chemistry

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Sandy Asher

Distinguished Professor

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701 CHVRN
Chevron Science Center
219 Parkman Avenue

Pittsburgh, PA 15260
412-624-8570

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Research Overview

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 bothfundamental 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

  • 14th Henry Kuivila Lecturer, University at Albany, SUNY, 2016
  • Society for Applied Spectroscopy Honorary Membership Award, 2016
  • Society of Analytical Chemists of Pittsburgh (SACP) Award in Analytical Chemistry, 2016
  • FACSS Charles Mann Award for Applied Raman Spectroscopy
, 2015
  • 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

“Monomeric Polyglutamine Structures that Evolve into Fibrils,” D. Punihaole, R. Jakubek, R. Workman, L. Marbella, P. Campbell, J. Madura, S. Asher , J. Phys. Chem. B., Vol. 121, 2017, Pages 5953-5967
“Ultraviolet Raman Wide-Field Hyperspectral Imaging Spectrometer for Standoff Trace Explosive Detection,” K.T. Hufziger, S.V. Bykov, S.A. Asher , Applied Spectroscopy, Vol. 71, 2017, Pages 173-185
“Aluminum Film-Over-Nanosphere Substrates for Deep-UV Surface-Enhanced Resonance Raman Spectroscopy,” B. Sharma, M.F. Cardinal, M. Ross, A. Zrimsek, S. Bykov, D. Punihaole, S. Asher, G. Schatz, R. Van Duyne , NanoLetters, Vol. 16, 2016, Pages 7968-7973
“Photonic Crystal Protein Hydrogel Sensor Materials Enabled by Conformationally Induced Volume Phase Transition,” Z. Cai, L.A. Luck, D. Punihaole, J.D. Madura and S.A. Asher , Chemical Science, Vol. 7, 2016, Pages 4557-4562
“Visual Detection of 2,4,6-trinitrotolune by Molecularly Imprinted Colloidal Array Photonic Crystal,” W. Lu, S. Asher, Z. Meng, Z. Yan, M. Xue, L. Qiu and D. Yi , J. Hazardous Materials, Vol. 316, 2016, Pages 87-93
“Polyglutamine Fibrils: New Insights into Antiparallel B-Sheet Conformational Preference and Side Chain Structure,” D. Punihaole, R.J. Workman, Z. Hong, J.D. Madura and S.A. Asher , J. Phys. Chem. B., Vol. 120, 2016, Pages 3012-3026
“Review of Explosive Detection Methodologies and the Emergence of Standoff Deep UV Resonance Raman,” K.L. Gares, K.T. Hufziger, S.V. Bykov and S.A. Asher , J. Raman Spectroscopy, Vol. 47, 2016, Pages 124-141
“Glutamine and Asparagine Side Chain Hyperconjugation-Induced Structurally Sensitive Vibrations,” D. Punihaole, Z. Hong, R.S. Jakubek, E.M. Dahlburg, S. Geib and S.A. Asher , J. Phys. Chem. B., Vol. 119, 2015, Pages 13039-13051
“A Photonic Crystal Protein Hydrogel Sensor for Candida albicans,” Z. Cai, D.H. Kwak, D. Punihaole, Z. Hong, S.Velankar, X. Liu and S.A. Asher , Angewandte Chemie International Edition, Vol. 54, 2015, Pages 13036-13040
“Removable Interpenetrating Network Enables Highly-Responsive 2-D Photonic Crystal Hydrogel Sensors,” A.E. Coukouma, N.L. Smith and S.A. Asher , Analyst, Vol. 140, 2015, Pages 6517-6521
“Compact Solid-State 213 nm Laser Enables Standoff Deep Ultraviolet Raman Spectrometer: Measurements of Nitrate Photochemistry,” S.V. Bykov, M. Mao, K.L. Gares and S.A. Asher, Applied Spectroscopy, Vol. 69, 2015, Pages 895-901
“Two-Dimensional Photonic Crystal Chemical and Biomolecular Sensors,” Z. Cai, N.L. Smith, J.-T. Zhang, S.A. Asher, Analytical Chemistry, Vol. 87, 2015, Pages 5013-5025
“UV Resonance Raman Investigation of the Aqueous Solvation Dependence of Primary Amide Vibrations,” D. Punihaole, R.S. Jakubek, E.M. Dahlburg, Z. Hong, N.S. Myshakina, S. Geib and S.A. Asher, J. Phys. Chem. B., Vol. 119, 2015, Pages 3931-3939
“Solution and Solid Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) Ultraviolet (UV) 229 nm Photochemistry,” K.L. Gares, S.V. Bykov, T. Brinzer and S.A. Asher, Applied Spectroscopy, Vol. 69, 2015, Pages 545-554
“Two-dimensional Colloidal Crystal Heterostructures,” F. Xue, S.A. Asher, Z. Meng, F. Wang, W. Lu, M. Xue, F. Qi, RSC Advances, Vol. 5, 2015, Pages 18939-18944
“Dependence of Raman and Resonance Raman Intensities on Sample Self-Absorption,” Z. Hong, S.A. Asher, Applied Spectroscopy, Vol. 69, 2015, Pages 75-83
“Two-Dimensional Photonic Crystal Sensors for Visual Detection of Lectin Concanavalin A,” J.T. Zhang, Z. Cai, D.H. Kwak, H. Liu, S.A. Asher, Analytical Chemistry, Vol. 86, 2014, Pages 9036-9041
“Sodium Dodecyl Sulfate Monomers Induce XAO Peptide Polyproline II to α-Helix Transition,” Z. Hong, K. Damodaran, S.A. Asher, J. Phys. Chem. B., Vol. 118, 2014, Pages 10565-10575
“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