Improved atomic force microscopy for probing single biomolecules.

摘要

The atomic force microscope (AFM) is a useful tool for probing the structural and mechanical properties of individual biological molecules in solution with nanometer spatial and piconewton force resolution. However, the measurement environment, a room temperature aqueous solution, severely limits the spatial, force, and temporal resolution of AFM measurements. This thesis outlines the development and implementation of AFMs that employ smaller cantilevers to allow for faster and more sensitive measurements of the properties of single biomolecules.; Chapter 1 outlines the design of a prototype AFM designed for small cantilevers. Chapter 2 introduces a process for fabricating small cantilevers and demonstrates that they can be used to measure smaller forces than larger conventional cantilevers. Chapter 3 shows that smaller cantilevers can be used for faster imaging and force spectroscopy of single biomolecules in solution. Chapter 4 shows the use of force spectroscopy to probe the inorganic layers between tablets in cleaved abalone shell making possible the theory that modular proteins may be responsible for abalone's spectacular strength. Finally, Chapter 5 presents the use of small cantilevers to observe, in real time, the interactions between individual protein molecules. These experiments suggest that for some biological systems it is possible to use the atomic force microscope to study protein dynamics at the single molecule level.