| The first synthetic polymer was Bakelite, phenol-formaldehyde resin, developed from 1905-1909 by chemist Leo Baekeland. Since then, polymer chemistry and technology has enhanced our way of life from transportation to food storage to communication and electronics. These advances have breached the barrier of pure polymer science and transcended into the fields of material science, physics, and biology. Currently, innovative research in polymers is enabling the nanotechnology revolution with a focus on the design and production of polymer thin films that have tunable properties. One such thin film is polymer brushes, and it is the focus of this dissertation. Polymer brushes, broadly defined, are an assembly of polymer chains anchored to a surface from some point in the chain, typically the end. They have desirable characteristics such as the ability to tether molecules to a substrate, or change the properties of a surface. Over the years, polymer brushes have found use in a number of applications such as in the development of new adhesive materials, biosurfaces and nonfouling biosurfaces. This work will illustrate several types of biosensors that have been enhanced through the incorporation of polymer brushes as well as investigate brushes as detached membranes. The first biosensor is an electrochemical detector is based on the intrinsic catalytic activity of antibodies. As a means of amplifying the signal, polymer brushes have been integrated to bind the antibodies to the surface as well as to prevent non-specific adsorption of other antibodies or contaminants that may be present in the test fluid. A second device includes a PEDOT:PSS based microelectrode which measures neuronal activities in vivo. This requires the tethering of glucose oxidase by brushes for specific charge exchange reactions to occur between the biological media and the conducting polymer. The third sensor uses functionalized polymer brushes to act as a scaffold for monitoring cellular motility. Lastly, we have developed a method of detaching polymer brushes for further exploration. This method provides the opportunity to test initiator quality, immobilization conditions, optimization parameters, and has provided insight to the nature of polymer brushes in a stretched state. |
