The research objective of this award is to utilize advanced methods of control engineering to enable a new performance regime for feedback tracking microscopy. Feedback tracking microscopy is a powerful new technique for studying the dynamics of individual macromolecules, which has already begun to make significant new contributions to our understanding of biological macromolecules such as DNA. Prior experiments in this area have been limited to the study of relatively large molecules and have required the use of many fluorescent dyes to label the molecule under study. The technical advances we will pursue under this NSF award will make it possible to apply feedback tracking microscopy to a wide range of molecules of moderate size using only a few fluorescent dyes for labeling. We will make these advances by applying modern methods of control theory to design improved feedback tracking algorithms, and through the development of advanced signal-processing electronics and motion-control hardware. Deliverables will include publications on the improved algorithms and apparatus, as well as more detailed technical documentation to be made freely available in electronic format.
If successful, the results of this research will enable new experiments in single-molecule biophysics and biochemistry, making it possible to apply feedback tracking microscopy for example to individual enzymes and ribozymes. Feedback tracking can be used greatly to enhance the sensitivity of traditional optical measurement techniques such as fluorescence correlation spectroscopy (FCS) and fluorescence resonance energy transfer (FRET). It is reasonable to hope that tracking-FCS and tracking-FRET measurements on single enzymes/ribozymes will deepen our understanding of stochastic kinetics and persistent heterogeneity in these important classes of biomolecules. The PI will incorporate the results of such work in his introductory-graduate level course on applied control theory, and the graduate student funded by this NSF award will benefit from a highly interdisciplinary training at the interface of modern engineering and biophysics/biochemistry.
