Catherine J. Murphy
Peter C. and Gretchen Miller Markunas Professor of Chemistry
Affiliate, Materials Science and Engineering
Affiliate, Micro and Nanotechnology Laboratory
associate director, MAterials Research Laboratory
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.
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.
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.
Sivapalan, S. T.; Vella, J. H.; Yang, T. K.; Dalton, M. J.; Haley, J. E.; Cooper, T. M.; Urbas, A. M.; Tan, L.-S.; Murphy, C. J. “Off-resonance two-photon absorption cross section enhancement of an organic chromophore on gold nanorods,”J. Phys. Chem. Lett. 2013,4, 749-752.
Huang, J.; Park, J.; Wang, W.; Murphy, C. J.; Cahill, D. G. “Ultrafast Thermal Analysis of Surface Functionalized Gold Nanorods in Aqueous Solution,”ACS Nano 2013,7, 589-597.
Park, J.; Huang, J.; Wang, W.; Murphy, C. J.; Cahill, D. G. “Heat Transport Between Au Nanorods, Surrounding Liquids, and Solid Supports,”J. Phys. Chem. C 2012,116, 26335-26341.
Lohse, S. E.; Murphy, C. J. “Applications of Colloidal Inorganic Nanomaterials: From Medicine to Energy,”J. Am. Chem. Soc. 2012,134, 15607-15620.
Huang, J.; Jackson, K. S.; Murphy, C. J. “Polyelectrolyte Wrapping Layers Control Rates of Photothermal Molecular Release from Gold Nanorods,”Nano Lett. 2012,12, 2982-2987.
Yang, J. A.; Lohse, S. E.; Boulos, S. P.; Murphy, C. J. “The Early Life of Gold Nanorods: Temporal Separation of Anisotropic and Isotropic Growth Modes,”J. Cluster Sci. 2012,23, 799-809.
Sivapalan, S. T.; Vella, J. H.; Yang, T. K.; Dalton, M. J.; Swiger, R. N.; Haley, J. E.; Cooper, T. M.; Urbas, A. M.; Tan, L-S.; Murphy, C. J. “Plasmonic Enhancement of the Two Photon Absorption Cross Section of an Organic Chromophore using Polyelectrolyte-coated Gold Nanorods,”Langmuir2012,28, 9147-9154.
- 2013 Carol Tyler Award, International Precious Metals Institute
- 2012 James D. & Julia P. Morrison Lectureship, Carleton College
- 2011 Fellow of the American Chemical Society
- 2011 Lucy W. Pickett Lecturer, Mount Holyoke College
- 2011 Inorganic Nanoscience Award, given by the Division of Inorganic Chemistry, American Chemical Society
- AAAS Fellow, 2008
- USC Russell Award for Research in Science, Mathematics, and Engineering, 2005.
- Outstanding Undergraduate Research Mentor Award, University of South Carolina, 2003
- Michael J. Mungo Award for Excellence in Undergraduate Teaching, University of South Carolina, 2001
- Golden Key Faculty Award for the Integration of Research and Undergraduate Teaching, 1998
- Camille Dreyfus Teacher-Scholar Award, 1998-2000
- Alfred P. Sloan Foundation Research Fellow, 1997-1999
- Cottrell Scholar Award, 1996-2001
- National Science Foundation CAREER Award, 1995-1998
Catherine J. Murphy named #32 in Science Watch's "Top Chemists of the Decade, 2000-2010"
Catherine J. Murphy named #10 in Science Watch's "Top Materials Scientists of the Decade, 2000-2010"
Top Five ACS article by citations, National Chemistry Week, 2007: Murphy, C. J.; Sau, T. K.; Gole, A.; Orendorff, C. J.; Gao, J.; Gou, L.; Hunyadi, S. Li, T. "Anisotropic Metal Nanoparticles: Synthesis, Assembly, and Optical Applications", J. Phys. Chem. B 2005, 109, 13857-13870.