Curtis Shannon

Professor

Ph.D. 1988, University of Texas—Austin

Research Interests

Electroanalytical chemistry using chemically modified electrodes and interfaces. Specific projects involve the electrosynthesis of semiconductor nano films, bio/chemical sensor development, surface chemistry of polyoxometalates, nanoporous thin films for separations, and surface enhance Raman spectroscopy of bio/chemical interfaces.

The central theme of our research is controlling the chemical behavior of electrode surfaces at the atomic/molecular level. A wide range of analytical tools, including scanning probe microscopy (AFM and STM), surface plasmon resonance, quartz microbalance, Raman spectroscopy, and surface IR spectroscopy, are available in our laboratory.

1. Electrosynthesis of semiconductor thin films. The advantages of electrodeposition include growth at ambient temperature and pressure, deposition onto surfaces with complex topographies, and low cost. The widespread application of electrosynthesis hinges on overcoming two limitations: polycrystalline growth and contaminated deposits. We are attempting to address these two issues through achieving atomic-level control of the deposition process. We are currently investigating approaches based on the electrochemical analogs of atomic layer deposition and atomic layer epitaxy.

2. Micro-cantilever based chemical and biological sensors. Detection of chemical and biological species with microelectromechanical systems (MEMS) technology offers the prospect of a new class of sensors that are both highly sensitive and inexpensive. These microscale sensors utilize a surface-bound receptor molecule, specific to a particular analyte, and then employ a wide variety of physical and chemical mechanisms for detection and transduction of molecular recognition events into quantifiable analytical responses.

3. Polyoxometalate monolayers as model oxide surfaces. Polyoxometalates (POMs) are highly symmetric, stable, nanometer scale clusters with characteristic sizes and shapes that resemble discrete fragments of bulk metal oxide phases. POMs adsorbed on metal substrates are good models of metal oxide surfaces and excellent catalysts in their own right. Our interest stems from their use as electrocatalysts, with potential applications as general oxidation catalysts, and components of fuel cells and dye-sensitized solar cells.

4. Nanoporous thin films for separations. Novel membrane materials based on novel inorganic coordination polymers and Ru-containing molecular squares are being investigated as possible stationary phases for the separation of gaseous and liquid analytes in highly confined spaces such as on micro-chip analytical platforms.

5. Surface Enhanced Raman Spectroscopy. Recent advances in the growth of size monodisperse metal nanoparticles and nanoparticle arrays with well-defined optical properties has lead to renewed interest SERS as an analytical technique. We are investigating the use of SERS to probe chemical and biological interactions relevant in analytical chemistry, such as the interaction between bacteriophages and pathogenic bacteria.

Representative publications

C. Gu and C. Shannon, “Investigation of the Photocatalytic Activity of TiO2 - Polyoxometalate Systems for the Oxidation of Methanol”, J. Molec. Catal. A, 2006, 258, 321-324.

M. H. Hall, P. Shevlin, H. Lu, A. Gichuhi, and C. Shannon, “Electron Acceptor-Induced Isomerization of Aryl [6,5] Open Fulleroids to [6,6] Closed Methanofullerenes and the Electrochemical Evaluation of their Free Energy Difference”, J. Org. Chem., 2006, 71, 3357-3363.

S. Abaci and C. Shannon, “The Influence of Decanethiol/4-Aminothiophenol Mixed Monolayers on the Electrodeposition of Polyaniline Thin Films” Electrochimica Acta, 2005, 50(14), 2967-2973.

S. Abaci, L. Zhang and C. Shannon, “The Influence of Counter Anions on the Underpotential Deposition of Mercury(II) on Au(111): Temperature Dependent Studies” J. Electroanal. Chem. 2004, 571(2), 169-176.

A. R. Howells, A. Sankarraj and C. Shannon, “A di-Ruthenium-substituted Polyoxometalate as an Electrocatalyst for Oxygen Generation”, J. Am. Chem. Soc. 2004, 126, 12258-12259.