Protein Detection Using Dynamic DNA Assembly

  • Author / Creator
    Li, Feng
  • Dynamic DNA assemblies are useful to generate or amplify signals for detection of nucleic acids. However, application of DNA assemblies to proteins is more challenging. The major research goal of my thesis is to expand the scope of dynamic DNA assemblies to proteins. I developed a fluorescence turn-on assay and studied thermal stability of DNA functionalized gold nanoparticles (DNA-AuNPs) as a function of organosulfur anchor groups and DNA surface densities. An attempt to use DNA-AuNPs as detection probes in western blot protein analyses revealed nonspecific protein adsorptions. By applying dynamic DNA assembly to Aptamer-functionalized gold nanoparticles (Apt-AuNPs), I designed a competitive protection strategy that was able to effectively eliminate nonspecific protein adsorptions on Apt-AuNPs, enabling specific and sensitive detection of target proteins from human serum samples. To broaden the use of dynamic DNA assembly as tools for protein detection, I developed a binding-induced DNA strand-displacement strategy that could convert protein bindings to the release of pre-designed output DNA molecules. The output DNA molecules were used to trigger various DNA assemblies. Using this strategy, I developed a binding-induced strand-displacement beacon and a binding-induced catalytic DNA circuit, both of which could be used as isothermal and enzyme-free signal amplification strategies for protein detection. I have further developed a molecular translator that acted by binding-induced dynamic DNA assemblies on AuNPs, enabling highly sensitive and specific detection of different protein targets in homogeneous solutions. The techniques and strategies described in this thesis can be potentially used to construct a variety of protein-mediated DNA assemblies and nanostructures. A promising application is in the area of point-of-care diagnostics, taking advantage of binding-induced DNA assembly, molecular and/or signal amplification, and nanoparticle-based visualization.

  • Subjects / Keywords
  • Graduation date
    Spring 2013
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
  • Supervisor / co-supervisor and their department(s)
  • Examining committee members and their departments
    • McDermott, Mark T. (Chemistry)
    • Gibbs-Davis, Julianne M. (Chemistry)
    • Campbell, Robert E. (Chemistry)
    • Sweedler, Jonathan V. (Chemistry)