Analytical Chemistry: Environmental Monitoring
with Dr. Julie Layshock
Dr. Layshock researches chemicals of concern in the environment. The objectives are to measure and monitor contaminants that are harmful to human and environmental health. Projects include 1), assessing the concentrations, bioavailability, and degradation of chemicals of concern in environmental matrices,
2) measuring contaminant leachates from commercial products combined with toxicity testing, and 3) developing analytical techniques that enable research to be conducted in an environmentally friendly manner.
Physical Chemistry: Optical properties of plasmonic nanoparticles
with Dr. Paige Hall Osberg
Dr. Hall’s research interests focus on nanoparticles made of silver and gold. Silver and gold have incredible optical properties that make them appear colored on the nanoscale—gold nanoparticles, for example, often appear red, while silver nanoparticles are typically green. Importantly, when molecules bind to the surfaces of these nanoparticles, they change color. This property enables metallic nanoparticles to be used as sensing devices in a variety of applications.
Students in the Hall lab optimize the sensitivity of gold and silver nanoparticles by carefully tailoring their size and shape using either lithographic methods or wet chemistry. Once the nanoparticles are fabricated, they are characterized using electron microscopy and spectroscopic techniques. Ultimately, the nanoparticles are used in sensing applications: for example, current projects include the study of electron transfer reactions that occur in natural organic matter and the detection of protein biomarkers.
1. B. Miranda, N. Lawton, S. Tachibana, N. Swartz, W. P. Hall: Titration and HPLC Characterization of Kombucha Fermentation: A Laboratory Experiment in Food Analysis. J. Chem. Educ. 93, 1770- 1775 (2016)
2. J. Ruemmele, W. P. Hall,* L. Ruvuna, R. P. Van Duyne: A Localized Surface Plasmon Resonance Imaging Instrument for Multiplexed Biosensing. Analytical Chemistry 85, 4560-4566 (2013)
3. W. P. Hall; J. Modica; Y. Lin; J. N. Anker; M. Mrksich; R. P. Van Duyne: A Conformation- and Ion-Sensitive Plasmonic Biosensor. Nano Letters 11, 1098-1105 (2011)
4. W. P. Hall; S. Ngatia; R. P. Van Duyne: LSPR Biosensor Signal Enhancement Using Nanoparticle-Antibody Conjugates. J. Phys. Chem. C 115, 1410-1414 (2011)
5. D. E. Ashkenaz; W. P. Hall; C. L. Haynes; E. M. Hicks; A. D. McFarland; L. J. Sherry; D. A. Stuart; K. E. Wheeler; C. R. Yonzon; J. Zhao; H. A. Godwin; R. P. Van Duyne: Coffee Cup Atomic Force Microscopy. J. Chemical Education 87, 306-307 (2010)
6. J. N. Anker; W. P. Hall; M. Lambert; P. Velasco; W. Klein; R. P. Van Duyne: Detection and Identification of Bioanalytes with High Resolution LSPR Spectroscopy and MALDI Mass Spectrometry. J. Phys. Chem. C 113, 5891-5894 (2009)
7. J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, R. P. Van Duyne: Biosensing with Plasmonic Nanosensors. Nature Materials, 7, 442-453 (2008)
8. W. P. Hall; J. N. Anker; Y. Lin; J. Modica; M. Mrksich; R. P. Van Duyne: A Calcium-Modulated Plasmonic Switch. J. Am. Chem. Soc. 130, 5836-5837 (2008)
9. A. J. Haes, W. P. Hall, L. Chang, W. L. Klein, R. P. Van Duyne: A Localized Surface Plasmon Resonance Biosensor: First Steps Toward an Assay for Alzheimer’s Disease. Nano Letters 4, 1029-1034 (2004)
Biochemistry: Protein Structure-Function Relationships
with Dr. Jeannine Chan
Dr. Chan's research interests lie in the area of protein structure - function relationships of metalloenzymes. Studies in her lab focus on the bacterial enzymes of the global nitrogen cycle, the ecology of which can have substantial impacts to both agricultural productivity and water quality. Specifically, she is investigating the mechanism of the Mo-nitrogenase, which catalyzes biological nitrogen fixation (N2 to NH3), and the biosynthesis of nitrous oxide reductase, a copper-containing enzyme which catalyzes the last step of the denitrification pathway (N2O to N2).
Recent Presentations and Publications
Chan, J. M., Bollinger, J. A., Grewell, C. L., Dooley, D. M. (2004) Reductively activated nitrous oxide reductase reacts directly with substrate. J. Am. Chem. Soc. 126, 3030-3031.
Sorlie, M., Chan, J. M., Wang, H., Seefeldt, L. C., Parker, V. D. (2003) Elucidating thermodynamic parameters for electron transfer proteins using isothermal titration calorimetry: Application to the nitrogenase Fe protein. J. Biol. Inorg. Chem. 8, 560-566.
Chan, J. M., Wu, W., Dean, D. R., and Seefeldt, L. C. (2000) Construction and characterization of a heterodimeric Fe protein: Defining roles for ATP in nitrogenase catalysis. Biochemistry 39, 7221-7228.
Christiansen, J., Chan, J. M., Seefeldt, L. C., and Dean, D. R. (2000) The role of the MoFe protein a-125Phe and beta-125Phe residues in Azotobacter vinelandii MoFe protein-Fe protein interaction. J. Inorg. Biochem. 80, 195-204.
Chan, J. M., Christiansen, J., Dean, D. R., and Seefeldt, L. C. (1999) Spectroscopic evidence for changes in the redox state of the nitrogenase P-cluster during turnover. Biochemistry 34, 5779-5785.
Chan, J. M., Ryle, M. J., and Seefeldt, L. C. (1999) Evidence that MgATP accelerates primary electron transfer in a Clostridium pasteurianum Fe protein-Azotobacter vinelandii MoFe protein nitrogenase tight complex. J. Biol. Chem. 274, 17593-17598.
Inorganic Chemistry: Synthesis of Biomimetic Polymers
with Dr. Joel Gohdes
Students working with Dr. Gohdes are trying to develop metal containing polymers that mimic the reactivity of naturally occurring proteins and enzymes. One of our initial targets, hemocyanin, is a copper containing protein responsible for oxygen transport in mollusks. Our approach entails synthesizing copper containing molecules that are then embedded in polymers. We follow the reactivity by monitoring the UV-vis spectrum as we expose these materials to different conditions. To the right is the structure of a hydroxide-bridged, copper dimer synthesized for this project.
Recent Presentations and Publications
"The synthesis and catalytic activity of a novel iron(II) molecularly imprinted polymer," Adam Glass and Joel Gohdes, Inorganic Poster session, 231st National American Chemical Society Meeting, Atlanta, GA, March 2006
"Complexes covalently bound to silica surfaces: a new approach to a dioxygen-binding catalyst," Erik Yukl and Joel Gohdes, 229st National American Chemical Society Meeting, San Diego, CA, March 2005
"Synthesis and dioxygen reactivity of a copper-containing polymer," Justin Crossland and Joel Gohdes, 227st National American Chemical Society Meeting, Anaheim, CA, March 2004
Disalvo, D.; Dellinger, D.B.; and Gohdes, J.W. "Catalytic Epoxidations of Styrene Using a Manganese Functionalized Polymer" Reactive and Functional Polymers, 53(2-3), 2002, 103-112.
Joel W. Gohdes, Brandy L. Duran, Noline C. Clark, Thomas W. Robison, Barbara F. Smith, and Nancy N. Sauer.,"Synthesis and Metal Binding properties of Novel Sulfur-Containing Water Soluble Polymers" Separation Science and Technology, 36(12), 2001, 2647-2658.
Physical Chemistry: Surface Chemistry Research: Spectroscopy and microscopy of liquid/solid interfaces
with Dr. Kevin E. Johnson
Students in Dr. Johnson's laboratory participate in research that investigates the molecular structure at the interface between solids and liquids. At an interface the structure of both the solid and liquid differ from that in the bulk material. The study of interfacial structure has bearing on the understanding of electrode surfaces, solid-state sensors, as well as cell surfaces in biological chemistry.
Student researchers will employ two techniques to study molecules at interfaces. Scanning tunneling microscopy (STM) and atomic force microscopy (AFM) are both scanning probe microscopy techniques that allow for the imaging of molecular structure of surfaces in situ. It is also possible to measure the molecularvibrations at interfaces using infrared reflection absorption spectroscopy (IRRAS) and surface enhanced Raman spectroscopy (SERS).
The surfaces studied are Self-Assembled Monolayers (SAMs); that is a single molecular layer on a well defined metal surface.
Kevin E. Johnson "Projects in General Chemistry Activity Sessions: Putting Theory into Practice" Presented at The 16th Biennial Conference on Chemical Education in Ann Arbor, Michigan, 31 July 2000.
Kevin E. Johnson "Electrolyte influence on lithium-ion batteries: SEI formation, damage to graphite electrodes, and the semi-empirical ethylene carbonate reduction pathway" Poster Presented at The Sigma Xi Forum and Annual Meeting in Raleigh, NC, 8-11 November 2002.
Kevin E. Johnson "Electrolyte influence on lithium-ion batteries: SEI formation, damage to graphite electrodes, and the semi-empirical ethylene carbonate reduction pathway" Poster presented at The Gordon Conference on Electrochemistry in Ventura, CA, 20-25 January 2003.
Kevin E. Johnson "Surface vibrational spectroscopy of nonaqueous electrolytes under potential control" Poster presented at The National American Chemical Society Meeting in Orlando, FL, 7-10 ASpril 2002.
Kevin E. Johnson "Implementation of model research projects in the general chemistry laboratory" Presented at The 17th Biennial Conference on Chemical Education in Bellingham, Washington, 29 July 2002.
Natural Products Synthesis as well as Structure - Activity Relationship (SAR) Studies of Antioxidant Agents
with Dr. Roxana Ciochina
The main focus of our research is synthesis of natural products with interesting biological properties. Laurenditerpenol is a natural product that potentially inhibits HIF - 1, a key factor in cancer progression. We try to synthesize laurenditerpenol by using the Diels - Alder reaction in the key steps of the synthesis. Students will have the chance to explore a wide variety of organic reactions, almost all studied in their sophomore courses, with a main focus on the Diels - Alder reaction.
Our group also developed a series of curcumin derivatives and is currently looking into their antioxidant properties as well as antimicrobial, anti-inflammatory, and carcinogenic properties. Some curcumin derivatives showed a strong fluorescence and we have already started looking into their optical properties and their potential uses as fluorescent dyes in biomedical research.