ENZYMATIC MODIFICATION AND X-RAY PHOTOELECTRON-SPECTROSCOPY ANALYSIS OF A FUNCTIONALIZED POLYDIACETYLENE THIN-FILM

The mild conditions and specificity of biological catalysts are attrac tive incentives for their use in the formation of surfaces with well-d efined chemical functionality. Herein, we describe the synthesis, char acterization, and enzymatic modification of a functionalized polymeric bilayer assembly. The assembly is composed of a self-assembled monola yer of octadecylsilane and a Langmuir-Blodgett monolayer of polydiacet ylene functionalized with the dipeptide phenylalanine-alanine (Phe-Ala ). We demonstrate via X-ray photoelectron spectroscopy surface analysi s that the surface-bound Phe-Ala dipeptide is a substrate for specific cleavage by the enzyme subtilisin BPN'. In-situ surface transformatio ns via enzymatic synthesis or cleavage offer an alternative to chemica l treatments of organic thin films.