David R. Walt | Department of Chemistry

Faculty
	David R. Walt Department of Chemistry Pearson Chemistry Laboratory 62 Talbot Avenue Tufts University Medford, MA 02155 Office: P-309 Tel: 617-627-3470 Fax: 617-627-3443 E-mail: david.walt@tufts.edu Research Homepage
Current Appointments Robinson Professor of Chemistry, Department of Chemistry Howard Hughes Medical Institute Professor Adjunct Professor of Biomedical Engineering Education Postdoctoral Research Associate, 1979-81, Massachusetts Institute of Technology, Cambridge, MA Ph.D., 1979 (Chemical Biology), SUNY at Stony Brook, Stony Brook, New York B.S. 1974 (Chemistry), University of Michigan, Ann Arbor, Michigan Research Interests Bioanalytical Chemistry, Materials Chemistry, Biochemistry and Nanoscience. The Walt group's research effort employs optical fiber microarrays for the detection and analysis of single molecules. Single enzyme molecules are enclosed with fluorogenic substrate in an array of thousands of individually addressable microchambers etched into a glass optical fiber bundle. The large array size provides excellent statistics. The substrate turnover in the microchambers can be monitored with fluorescence microscopy. The results of these experiments provide mechanistic insight into enzyme mechanisms. In addition to these fundamental studies, they have also developed single molecule methods for high sensitivity DNA and protein detection. In another project the Walt lab is investigating the limits to creating high-density sensing arrays containing thousands of microsensors and nanosensors and are preparing arrays to perform high density nucleic acid and protein analysis. One application of this effort is an integrated diagnostic platform for performing medical diagnostics using saliva as a sample instead of blood. The arrays can also be used to study living cells, both as cell populations as well as individual cells, and analyze the contents of individual cells by integrating microfluidics with single molecule detection. They are also studying the behavior of large numbers of cells to understand the distribution of cell behaviors in a population.l Selected Recent Publications "InfoBiology by printed arrays of microorganism colonies for timed and on-demand release of messages", M. A. Palacios, E. Benito-Peña, M. Manesse, A. D. Mazzeo, C. N. LaFratta, G. M. Whitesides, and D. R. Walt, Proc Natl Acad Sci USA, 2011, 108, 16510-16514. "Detection and Classification of Ignitable Liquid Residues using a Fluorescence-Based Vapor-Sensitive Microsphere Array", M. J. Aernecke, D. R. Walt, J. Forensic. Sci., 2010, 55, 178-184. "Synthesis and Biological Testing of Penicillins: An Investigative Approach to the Undergraduate Teaching Laboratory" , R. D. Whitaker, L. Truhlar, D. Yuksel, D. R. Walt, M. Williams, J. Chem. Edu., 2010, 87, 634-636. "Analytical Chemistry on the Femtoliter Scale", H. H. Gorris, D. R. Walt. Ang. Chemie, 2010, 49, 3880-3895. "Visualizing Fluorescence: Using a Homemade Fluorescence 'Microscope' to View Latent Fingerprints on Paper" C. N. LaFratta, D. R. Walt, S. P. Huh, A. Mallillin, P. Riviello. J. Chem. Edu., 2010, 87, 1105-1107. "Single-molecule enzyme-linked immunosorbent assay detects serum proteins at subfemtomolar concentrations", D. M. Rissin, C. W. Kan, T. G. Campbell, S. C. Stuart, D. R. Fournier, L. Song, T. Piech, P. P. Patel, L. Chang, A. J. Rivnak, E. P. Ferrell, J. D. Randall, G. K. Provuncher, D. R. Walt, D. C. Duffy, Nature Biotechnology, 2010, 28, 595-599. "Optical-fiber arrays for vapor sensing", Aernecke, Matthew J.; Walt, David R. Sensors and Actuators, B: Chemical, 2009, B142, 464-469. "Infochemistry and infofuses for the chemical storage and transmission of coded information" Thomas, Samuel W., III; Chiechi, Ryan C.; Lafratta, Christopher N.; Webb, Michael R.; Lee, Andrew; Wiley, Benjamin J.; Zakin, Mitchell R.; Walt, David R.; Whitesides, George M. Proc. Natl. Acad. Sci. USA, 2009, 106, 9147-9150. "Intelligent Medical Diagnostics via Molecular Logic", Konry, Tania; Walt, David R., J. Amer. Chem. Soc., 2009, 131, 13232-13233. Additional publications can be found HERE Selected Media & E/PO Links - BBC News "Fluorescing Bacteria Used to Encode Secret Messages" 27 Sept 2011 - ACS Webinar "A Life of Inovation - Finding Your Passion" David Walt 17 June 2010 - "Working with Local Public Schools" Tufts Daily, 31 March 2010 - Observing Single Enzymes At Work Chem. Eng. News, 29 Oct 2007