Molecular Recognition Between a Biotinylated Polythiophene Copolymer andPhycoerythrin Utilizing the Biotin-Streptavidin Interaction

摘要

The interaction of photoactive proteins with an electroactive matrix is valuablein leading to potential technological applications in opto-electronic signal transduction for optical displays, color mirnicking, biosensor, and protein research applications. In this study, the Langmuir-Blodgett technique is used to couple these components through the well known biotin-streptavidin complexation. Biotinylated copolymers of 3-substituted thiophenes have been synthesized both to enhance mechanical film integrity and to provide the electroactive matrix for attachment of the antennae protein, phycoerythrin. It has been determined that biotinylation of the thiophene copolymers improves their film forming properties and results in stable monolayers. Pressure-area isotherms indicate that protein interaction within the polymer monolayer is occurring with the streptavidin and phycoerythrin proteins. Fluorescence spectroscopy of transferred films confirms the presence of phycoerythrin in the final molecular assemblies. Each stage of protein binding to the biotinylated copolymer monolayer could be monitored through fluorescence microscopy at the air-water interface. These results suggest that this copolymer system is a promising material for integrating virtually any biotinylated macromolecular system to an electroactive matrix. In addition, this copolymer system may be fine-tuned to maximize protein integration by varying the distance between biotin functionalities and/or the length of the biotin spacer arm.