Catherine Murphy
Peter C. and Gretchen Miller Markunas Professor of Chemistry
Professor Murphy received two B.S. degrees, one in chemistry and one in biochemistry, from the University of Illinois in 1986. She received her Ph.D. from the University of Wisconsin in 1990. From 1990-1993, she was first an NSF and then an NIH postdoctoral fellow at the California Institute of Technology. From 1993-2009 Professor Murphy was a faculty member in the Department of Chemistry and Biochemistry at the University of South Carolina. In August 2009 she joined the faculty of the Department of Chemistry at the University of Illinois.
Research
Our research is at the interface of materials chemistry, inorganic chemistry, biophysical chemistry and nanotechnology. Our primary goal is to develop inorganic nanomaterials for biological and energy-related applications, and understand the chemical interactions of these nanomaterials with their surroundings. A diverse range of projects are currently pursued in the group:
Inorganic Nanoparticle Fabrication and Functionalization.
"Finely-divided metals" such as gold, silver and copper have been known since Roman times for their brilliant colors. These brilliant colors arise fundamentally from the interaction of light with the conduction band electrons in these nanoscale metal particles, producing what is known as a plasmon resonance at particular optical frequencies. Nanorods, compared to nanospheres, have multiple plasmon bands whose position and intensity are intimately connected to the size, shape, degree of aggregation, and local dielectric environment of the nanorods. The absorption and scattering of light by gold and silver nanorods can be tuned throughout the visible and near-infrared portions of the electromagnetic spectrum. We have developed a set of synthetic approaches to fabricate gold and silver nanorods of controlled size and shape in high yields. Molecules can be placed on the nanorod surface using covalent attachment chemistries or polyelectrolyte layer-by-layer adsorption to position them at desired distances, and possibly orientations, from the nanoscale metal surface. On-particle reactions are being explored to improve the compatibility and ease of processing of these materials. Copper oxide and other oxide nanomaterials are of interest for solar energy and energy storage applications.
Cellular Imaging, Chemical Sensing, and Photothermal Therapy Using Gold Nanorods.
The strong plasmon bands of noble metal nanoparticles make them ideal for biological sensing and imaging applications. We have used the elastic light scattering properties of gold nanorods as "nano strain gauges" to measure the deformation of soft matrices by living cells. The inelastic light scattering (Raman) properties of gold nanorods can be used to interrogate the local chemical environment of the nanorods. Irradiation into nanorod plasmon bands causes large temperature jumps in the local environment, which we have exploited as a way to kill multidrug-resistant bacteria (once the nanorods are surface-modified to recognize the bacteria).
Environmental Implications of Nanoparticles.
How are nanoparticles distributed and modified in complex biological systems? Can nanoparticles sequester or deliver small molecules across interfaces? How do these processes depend, if at all, on nanoparticle size, shape, aggregation state, and surface chemistry? These are questions that we seek to address using a battery of analytical, physical, and biochemical techniques.
Publications
Wilson, C. G.; Sisco, P. N.; Gadala-Maria, F. A.; Murphy, C. J.; Goldsmith, E. C. "Polyelectrolyte-Coated Gold Nanorods and Their Interactions with Type I Collagen," Biomaterials 2009, 30, 5639-5648.
Ferry, J. L.; Craig, P; Hexel, C.; Sisco, P. N.; Frey, R.; Pennington, P; Fulton, M.; Scott, G.; Decho, A.; Kashiwada, S.; Murphy, C. J.; Shaw, T. J. "Transfer of Gold Nanoparticles from the Water Column to the Estuarine Food Web," Nature Nanotechnology 2009, 4, 441-444.
Murphy, C. J. "Spatial Control of Chemistry on the Inside and Outside of Inorganic Nanocrystals," ACS Nano 2009, 4, 770-774.
Sisco, P. N.; Murphy, C. J. "Surface Coverage Dependence of Surface-Enhanced Raman Scattering from Gold Nanocubes on Self-Assembled Monolayers of Analyte," J. Phys. Chem. A, 2009, 113, 3973-3978.
Alkilany, A. M.; Nagaria, P.; Hexel, C. R.; Shaw, T. J.; Murphy, C. J.; Wyatt, M. D. "Cellular Uptake and Cytotoxicity of Gold Nanorods: Molecular Origin of Cytotoxicity and Surface Effects," Small 2009, 5, 701-708.
Gole, A.; Agarwal, N.; Nagaria, P.; Wyatt, M. D.; Murphy, C. J. "One-Pot Synthesis of Silica-Coated Magnetic Plasmonic Tracer Nanoparticles," Chem. Commun. 2008, 6140-6142.
Murphy, C. J.; Gole, A. M.; Stone, J. W.; Sisco, P. N.; Alkilany, A. M.; Goldsmith, E. C.; Baxter, S. C. "Gold Nanoparticles in Biology: Beyond Toxicity to Cellular Imaging," Acc. Chem. Res. 2008, 41, 1721-1730.
Sisco, P. N.; Minrova, E.; Wilson, C.; Murphy, C. J.; Goldsmith, E. C. "The Effect of Gold Nanorods on Cell-Mediated Collagen Remodeling," NanoLetters 2008, 8, 3409-3412.
Alkilany, A. M.; Frey, R. L.; Ferry, J. L.; Murphy, C. J. "Gold Nanorods as Nanoadmicelles: 1-Naphthol Partitioning into a Nanorod-Bound Surfactant Bilayer," Langmuir 2008, 24, 10235-10239.
Norman, R. S.; Stone, J. W.; Gole, A.; Murphy, C. J.; Sabo-Attwood, T. "Photothermal Destruction of the Bacterium Pseudomonas Ariginosa by Gold Nanorods," NanoLetters 2008, 8, 302-306.
Berg, M. A.; Coleman, R. S.; Murphy, C. J. "Nanoscale Structure and Dynamics of DNA," PhysChemChemPhys 2008, 10, 1229-1242.
Gole, A.; Murphy, C. J. "Azide-Derivatized Gold Nanorods: Functional Materials for 'Click' Chemistry," Langmuir 2008, 24, 266-272.
Murphy, C. J.; Gole, A. M.; Hunyadi, S. E.; Stone, J. W.; Sisco, P.; Alkilany, A.; Hankins, P. L.; Kinard, B. "Chemical Sensing and Imaging with Metallic Nanorods," Chem. Comm. 2008, 544-557.
Mahtab, R.; Sealey, S. M.; Hunyadi, S. E.; Kinard, B.; Ray, T.; Murphy, C. J. "Influence of the Nature of Quantum Dot Surface Cations on Interactions with DNA," J. Inorg. Biochem. 2007, 101, 559-564.
Stone, J. W.; Sisco, P. N.; Goldsmith, E. C.; Baxter, S. C.; Murphy, C. J. "Using Gold Nanorods to Probe Cell-Induced Collagen Deformation," NanoLetters 2007, 7, 116-119.
Awards
- National Science Foundation CAREER Award, 1995-1998
- Cottrell Scholar Award, 1996-2001
- Alfred P. Sloan Foundation Research Fellow, 1997-1999
- Camille Dreyfus Teacher-Scholar Award, 1998-2000
- Golden Key Faculty Award for the Integration of Research and Undergraduate Teaching, 1998
- Michael J. Mungo Award for Excellence in Undergraduate Teaching, University of South Carolina, 2001
- Outstanding Undergraduate Research Mentor Award, University of South Carolina, 2003
- USC Russell Award for Research in Science, Mathematics, and Engineering, 2005.
- AAAS Fellow, 2008
