Département de chimie moléculaire

The electropolymn. of an enzyme-amphiphilic pyrrole ammonium-laponite nanoparticles mixt. preadsorbed on the electrode surface provides the simultaneous immobilization of the enzyme and the hydrophilic laponite-clay-nanoparticles in a functionalized polypyrrole film. The presence of incorporated laponite particles within the electrogenerated polymer induces a strong improvement of the anal. performances (Imax and sensitivity) of amperometric biosensors based on polyphenol oxidase. These beneficial effects have been attributed to a marked enhancement of the apparent specific activity of the immobilized enzyme (from 0.21 to 0.85{%} of the specific activity of the free enzyme), the permeability of the host polymer being unchanged. This strategy of biosensor performance improvement was tested with cholesterol oxidase as an enzyme model. The presence of laponite additive in the poly(amphiphilic pyrrole) host matrix induces a similar enhancement of sensitivity and Imax for cholesterol biosensing as well as a large improvement of the storage stability of the polypyrrole-cholesterol oxidase electrode. [on SciFinder(R)]