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

  • 2018 Raman Lifetime Award, International Conference of Raman Spectroscopy (ICORS)
  • 2018 Applied Spectroscopy "Editor's Choice" Award: "Ultraviolet Raman Wide-Field Hyperspectral Imaging Spectrometer for Standoff Trace Explosive Detection", authors-Kyle T. Hufziger, Sergei V. Bykov and Sanford A. Asher
  • 2018 Society for Applied Spectroscopy “Pillars of Spectroscopy” Tour Speaker
  • 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

“Solid Deep Ultraviolet Diffracting Inverse Opal Photonic Crystals,” Applied Nano Materials 2018, 1, 7016-7024
“Ultraviolet Resonance Raman Spectroscopic Markers for Protein Structure and Dynamics,” R.S. Jakubek, J. Handen, S.E. White, S.A. Asher, I.K. Lednev Trends in Analytical Chemistry 2018, 103, 223-229
“Interaction Enthalpy of Side Chain and Backbone Amides in Polyglutamine Solution Monomers and Fibrils,” D. Punihaole, R.. Jakubek, R.J. Workman, S.A. Asher J. Phys. Chem. Lett. 2018, 9, 1944-1950
“Hydrophobic Collapse Initiates Poly(N-isopropylacrylamide) Volume Phase Transition Reaction Coordinate,” T-Y. Wu, A.B. Zrimsek, S.V. Bykov, R.S. Jakubek, S.A. Asher J. Phys. Chem. B. 2018, 122, 3008-3014
“Increased Volume Responsiveness of Macroporous Hydrogels,” A.E. Coukouma and S.A. Asher Sensors and Actuators B 2018, 255, 2900-2903
“Debye Ring Diffraction Elucidation of 2D Photonic Crystal Self-Assembly and Ordering at the Air-Water Interface,” N.L. Smith, A.E. Coukouma, S. Dubnik and S.A. Asher Physical Chemistry Chemical Physics 2017, 19, 31813-31822
“UV Resonance Raman Investigation of Pentaerythritol Tetranitrate Solution Photochemistry and Photoproduct Hydrolysis,” K.L.Gares, S.V. Bykov and S.A. Asher J. Phys. Chem A. 2017, 121, 7889-7894
“Responsive Photonic Crystal Carbohydrate Hydrogel Sensor Meterials for Selective and Sensitive Lectin Protein Detection,” ACS Sensors 2017, 2, 1474-1481
“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. 2017, 121, 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 2017, 71, 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 2016, 16, 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 2016, 7, 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 2016, 316, 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. 2016, 120, 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 2016, 47, 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. 2015, 119, 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 2015, 54, 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 2015, 140, 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 2015, 69, 895-901
“Two-Dimensional Photonic Crystal Chemical and Biomolecular Sensors,” Z. Cai, N.L. Smith, J.-T. Zhang, S.A. Asher Analytical Chemistry 2015, 87, 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. 2015, 119, 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 2015, 69, 545-554
“Two-dimensional Colloidal Crystal Heterostructures,” F. Xue, S.A. Asher, Z. Meng, F. Wang, W. Lu, M. Xue, F. Qi RSC Advances 2015, 5, 18939-18944
“Dependence of Raman and Resonance Raman Intensities on Sample Self-Absorption,” Z. Hong, S.A. Asher Applied Spectroscopy 2015, 69, 75-83
“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 2014, 68, 49-56