Département de chimie moléculaire

One challenging goal for the development of biosensors is the conception of three-dimensional biostructures on electrode surfaces. With the aim to develop 3D architectures based on single-walled carbon nanotubes (SWCNTs) frameworks a novel adamantane-pyrrole monomer was synthesized. After electrochem. polymn. at 0.95 V in acetonitrile, the resulting polypyrrole film provided affinity interactions with $\beta$-cyclodextrin. SWCNT coatings were thus functionalized with poly(adamantane-pyrrole) and applied to the anchoring of glucose oxidase (GOX), modified with $\beta$-cyclodextrin. By using this affinity system adamantine-cyclodextrin, $\beta$-cyclodextrin-modified gold nanoparticles were attached onto the functionalized SWCNT deposit as intermediate layer. This allows the immobilization of adamantane-tagged GOX. The responses of these biosensors to glucose were measured by potentiostating the modified electrodes at 0.7 V vs. SCE in order to oxidize the enzymically generated hydrogen peroxide in the presence of glucose and oxygen. The highest sensitivity and max. c.d. were recorded for the configuration based on $\beta$-cyclodextrin-modified gold particles as intermediate layer between adamantine-functionalized SWCNTs and GOX (31.02 mA M-1cm-2 and 350 $μ$A cm-2, resp.). The similar configuration without SWCNTs exhibits a sensitivity and Jmax of 0.98 mA M-1cm-2 and 75 $μ$A cm-2, resp. The resulting supramol. assemblies were characterized by SEM. Advantages and disadvantages of the different prepn. methods and the performance of each affinity sensor setup are discussed in detail. [on SciFinder(R)]