Département de chimie moléculaire

Single-walled carbon nanotubes were functionalized with biotin using either electropolymn. or formation of $π$-stacking interactions for the construction of biosensors. Thanks to the high affinity of the avidin-biotin interactions, a biotinylated glucose oxidase (B-GOX) as a biomol. model was immobilized on the biotinylated nanotubes. The influence of the biosensor configuration on their amperometric performances was investigated by changing the amt. of nanotubes and the nos. of avidin/B-GOX layers. By increasing the amt. of nanotube and avidin/B-GOX layers, both sensor setups show a perfect linear increase of immobilized enzymes reflecting a high reproducibility of the authors' systems. The highest sensitivities (up to 5.2 mA M-1 cm-2) and max. current densities (up to 55 $μ$A cm-2) were obtained using nanotube deposits modified by electrochem. coatings. Noncovalently functionalized biotin-nanotubes show a better permeability for the enzymically generated hydrogen peroxide. [on SciFinder(R)]