| In the first part of this dissertation, we investigated the structural basis of the outer membrane permeability for the bacterium Escherichia coli by atomic force microscopy (AFM). The surface of the bacterium is visualized with unprecedented detail at 50 and 5 Å lateral and vertical resolutions, respectively.; In the second part, we discussed a nanoengineering approach for supramolecular chemistry and self-assembly. The collective property and biofunctionality of molecular ensembles depend not only upon the individual molecular building blocks, but also upon the organization at molecular or nanoscopic level. Complementary to “bottom-up” approaches, nanofabrication explores if individual units such as small molecular ligands or large molecules such as proteins can be positioned with nanometer precision. The separation and local environment can be engineered to control subsequent intermolecular interactions. Feature sizes as small as 2 x 4 nm2 are produced. Proteins are aligned along a 10 nm wide line or within two-dimensional islands. The stability of the matrix and nanopatterns are also investigated. This nanofabrication methodology offers a new strategy in construction of two and three-dimensional supramolecular structures for cell, virus, and bacterial adhesion, as well as biomaterial and biodevice engineering. |
