Jeffrey Petty

Jeffrey Petty

Professor, Chemistry

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Dr. Jeffrey Petty is interested in the interface of physical chemistry, biochemistry, and inorganic chemistry. He trained with Brad Moore in the spectroscopy of atmospherically significant free radicals. He then continued his studies with Dick Keller in the area of ultrasensitive, laser-based biomolecular detection. Dr. Petty continues his studies with his students and colleagues in the area of silver cluster-DNA interactions. ​​​​

Transient Absorption Infrared Spectroscopy of Atmospheric Radicals

Spectroscopy and Structure of DNA-Bound Silver Clusters

Education

  • Ph.D., University of California, Berkeley
  • B.S., Furman University

Research

Our studies revolve around the small sizes of silver clusters. These molecular metals have discrete electronic states, localized optical transitions, and strong fluorescence. DNA strands serve two purposes: (1) Their nucleobases coordinate specific species, and specific sequences yield chromophores with spectra that span the visible and near-infrared spectral regions; (2) They direct cluster transformations via changes in their secondary structure. Our studies revolve around pairs of chromophores that interconvert via hybridization. These conjugate cluster-DNA chromophores are innovative because of two features – hybridization switches on fluorescence and two-color laser excitation enhances the overall cluster emission. Mass spectrometry and X-ray absorption spectroscopy establish the basis for the fluorescence switching. Changes in the stoichiometry, charge, and structure of pairs of dim/bright chromophores are investigated. Fluorescence correlation spectroscopy evaluates the basis for the two-color enhanced fluorescence. These two sets of studies will provide the foundation to develop a new class of optical sensors. These sensors will be used to detect low abundance microRNA sequences that are relevant for early cancer intervention.

DNA-Bound Silver Clusters: Time-resolved and Steady-State Spectroscopy, Electrospray Ionization Mass Spectrometry, Alternate DNA Structures

Publications

  • Tug-of-War between DNA Chelation and Silver Agglomeration in DNA–Silver Cluster Chromophores. J. T. Petty, D. Lewis, S. Carnahan, D. Kim and C. Couch. The Journal of Physical Chemistry B 2022 Vol. 126 Issue 21 Pages 3822-3830. DOI: 10.1021/acs.jpcb.2c01054
  • Interrupted DNA and Slow Silver Cluster Luminescence. D. Lewis, C. Setzler, P. M. Goodwin, K. Thomas, M. Branham, C. A. Arrington and J. T. Petty. The Journal of Physical Chemistry C 2023 Vol. 127 Issue 22 Pages 10574-10584. DOI: 10.1021/acs.jpcc.3c01050