Design of novel intelligent materials by incorporating biomolecules into electroactive polymeric thin film systems

The objective of this study is to create a novel class of intelligent materials by integrating two separate classes of intelligent materials; one biological, the other thin film conducting polymers. The first class, which includes DNA and the photoactive protein, phycoerythrin, possesses superior intelligent properties designed to function in cells specifically and efficiently in integrated macromolecular arrays. The second material is the polymeric thin film or two dimensional Langmuir-Blodgett (LB) monolayer film. The films are comprised of electroactive polymeric materials such as polypyrrole (PPy) and polyalkylthiophenes, that are derivatized with biotin. Biotinylated protein are stably attached to this monolayer film via a bridging streptavidin protein.; Polycation conducting polymers, oxidized polypyrrole and polyalkylthiophene, possess the ability to form complexes with polyanionic DNA molecules largely through electrostatic interactions. The results demonstrate the solution uptake and binding of {dollar}sp{lcub}32{rcub}{dollar}P radiolabeled double stranded DNA by conducting polymer thick films (50-100{dollar}mu{dollar}m). The DNA kinetics support a diffusion limited model for binding. The DNA binding levels increased in the same order as the conductivities of the polymer films, Polyundecylthiophene, Polyhexylthiopene, and PPy. In addition, DNA binding onto oxidized PPy film was diminished upon electrochemical reduction.; A novel hierarchical biomaterial capable of incorporating any biotinylated biomolecule was created. The strategy was to biotinylate one-dimensional electroactive polymers and use bridging streptavidin protein on LB organized films. The thiophene copolymeric systems which enable functionalization of other molecules and formation of good monolayers were employed. Biotinylated poly(3-methanolthiophene-co-3-hexylthiophene) (B-PMHT) and poly(3-methanolthiophene-co-3-undecylthiophene) (B-PMUT) demonstrated a significantly better isotherm implying superior molecular packing compared to poly(3-methanolthiophene-co-3-hexylthiophene) (PMHT) and poly(3-methanolthiophene-co-3-undecylthiophene) (PMUT) on the LB air-water surface. The isotherm showed significant area expansion when streptavidin was injected below the B-PMHT and B-PMUT monolayers in 0.1mM NaH{dollar}sb2{dollar}PO{dollar}sb4{dollar}/0.1M NaCl buffer (pH 6.8) subphase. Incorporation of biotinylated phycoerythrin (B-PE) into this novel biomaterial was then performed by binding the unoccupied biotin binding sites on the bound streptavidin (4 sites total). The pressure-area isotherm of the protein injected monolayer showed area expansion. A characteristic fluorescent emission peak at 576 nm was detected from the monolayer transferred onto a solid substrate. Fluorescence micrographs further confirmed the assembly of this complexation. (Abstract shortened by UMI.)...