Assistant Professor

Biography

I am a bioanlytical chemist with a research focus on the development and design of novel nanoparticle based methods of ultra-sensitive biomedical and environmental detection and analysis. Specifically, I exploit the unique optical properties of gold and silver structures such as intense absorption, wavelength selective photon scattering, localized surface plasmon resonance (LSPR), and the ability to support surface-enhanced Raman scattering (SERS). An important part of this research is the systematic investigation of the fundamental relationships between a particles physical properties (size, shape, composition) and its observed optical properties. The sensitivity of the LSPR to the dielectric environment enables us to create sensors capable of measuring binding events by monitoring shifts in the UV-Vis spectrum of the nanomaterial. The nanoparticles are functionalized e.g. with capture antibodies to make them sensitive only to specific target molecules. Single particle experiments have demonstrated zeptomole sensitivities.The intense electric fields generated localized surface plasmon are the single most important factor in observing the surface-enhanced Raman phenomenon. SERS is an attractive but under utilized- analytical technique because it generates unique vibrational spectra that can be used for unambiguous determination of analytes. In that regard, Raman spectroscopy is similar to infra-red absorbance spectroscopy, but enjoys the advantages of being able to operate in aqueous environments, and on opaque surfaces and materials (e.g. pharmaceutical tablets and coatings). In SERS, the analyte is placed at or near a nanoscale roughened noble metal surface, yielding an increase in intensity of ten to a million fold over standard Raman scattering. SERS position as the only vibrational spectroscopy capable of single-molecule is due to these enormous gains in signal.

Education / Degrees

  • B.A., Chemistry, English, and Philosophy, Wabash College, 1996
  • M.A., M. Litt, University of Aberdeen, 2001
  • Ph.D., Bioanalytical Chemistry, Indiana University, 2003
  • Courses Taught
  • Course Sections and Syllabi

    Fall 2017 Sections

    Summer 2017 Sections

    • CHEM-1212 (Principles of Chemistry II) Section: 01
    • CHEM-1212 (Principles of Chemistry II) Section: 02
    • CHEM-1212 (Principles of Chemistry II) Section: 03
    • CHEM-1212 (Principles of Chemistry II) Section: 04

    Spring 2017 Sections

    Fall 2016 Sections

    Summer 2016 Sections

    • CHEM-1211 (Principles of Chemistry I) Section: 01
    • CHEM-1211 (Principles of Chemistry I) Section: 02
    • CHEM-1211L (Principles of Chemistry I Lab) Section: 01

    Spring 2016 Sections

    Fall 2015 Sections

    • CHEM-1211K (Princ of Chemistry I) Section: 04G
    • CHEM-3310K (Analytical Chemistry) Section: 01W
    • CHEM-3310K (Analytical Chemistry) Section: 02W
    • CHEM-3550L (Physical Chemistry Lab) Section: 01W

    Summer 2015 Sections

    • XIDS-2002 (WDYKA: Materials Science) Section: E01
    • CHEM-5785 (Materials Science) Section: E01

    Spring 2015 Sections

    Fall 2014 Sections

    • CHEM-1211K (Princ of Chemistry I) Section: 05G
    • CHEM-3310K (Analytical Chemistry) Section: 01W
    • CHEM-3310K (Analytical Chemistry) Section: 02W

    Summer 2014 Sections

    • CHEM-1211 (Principles of Chemistry I) Section: 01
    • CHEM-1211 (Principles of Chemistry I) Section: 02
    • CHEM-1211L (Principles of Chemistry I Lab) Section: 01

    Spring 2014 Sections

    • CHEM-1211 (Principles of Chemistry I) Section: 01
    • CHEM-1211 (Principles of Chemistry I) Section: 02
    • CHEM-1211 (Principles of Chemistry I) Section: 03
    • CHEM-1211 (Principles of Chemistry I) Section: 04
    • CHEM-1211 (Principles of Chemistry I) Section: 05
    • CHEM-1211 (Principles of Chemistry I) Section: 06
    • CHEM-1211 (Principles of Chemistry I) Section: 07
    • CHEM-1211 (Principles of Chemistry I) Section: 08
    • CHEM-1211L (Principles of Chemistry I Lab) Section: 02
    • CHEM-3550L (Physical Chemistry Lab) Section: 01W
    • CHEM-4330K (Instrumental Analysis) Section: 01
    • CHEM-4985 (Sel Topics:Integrated Approach) Section: 01

    Fall 2013 Sections

    • CHEM-1211K (Princ of Chemistry I) Section: 01G
    • CHEM-3310K (Analytical Chemistry) Section: 01W
    • CHEM-3310K (Analytical Chemistry) Section: 02W

    Spring 2013 Sections

    • CHEM-1211K (Princ of Chemistry I) Section: 02G
    • CHEM-1212 (Principles of Chemistry II) Section: 01
    • CHEM-1212 (Principles of Chemistry II) Section: 02
    • CHEM-1212 (Principles of Chemistry II) Section: 03
    • CHEM-1212 (Principles of Chemistry II) Section: 04
    • CHEM-1212L (Principles of Chemistry II Lab) Section: 01
    • CHEM-3550L (Physical Chemistry Lab) Section: 01W
    • CHEM-4330K (Instrumental Analysis) Section: 01
  • Publication List

    Obie Okponyia, Brent M. Williams, Kellie Patton, and Douglas A. Stuart Fundamental Studies of Surface-enhanced Raman Scattering (SERS) using Aersolized Substrates. In Advanced Environmental, Chemical, and Biological Sensing Technologies IX. Edited by Tuan

    Brett Kimbrell, Chritopher M. Crittenden, Walter J. Steward, Farooq A. Khan, Anne C. Gaquere-Parker and Douglas A. Stuart Analysis of mixtures of C60 and C70 by a portable Raman spectrometer Nanoscience Methods Volume 3 (2014) , pp 40-46

    A. Vinyard, K.A. Hansen, R. Byrd, D.A. Stuart, J.E. Hansen (2014) Design of a Simple Cryogenic System for UltravioletVisible Absorption Spectroscopy with a Back-Reflectance Fiber Optic Probe, Appl. Spec. 68(1): 118-123. doi: 10.1366/13-07129

    "Raman Spectroscopy of Allotropes of Carbon: An Undergraduate Laboratory ".The Chemical Educator, Volume 19 (2014) pp 223-228 [View Publication]

  • Skills and Resources

    Instrumental Analysis

    Nanotechnology

    Research and application nanoscale materials.

    Chemometrics

    The application of multivariate techniques (PCA, PLS, etc) to complex chemical data sets.

    Raman Spectroscopy

    Application of Raman vibrational spectroscopy to analytical problems. Raman spectroscopy is an inelastic scattering technique that allows for unique identification of molecules based on their vibrational fingerprint.