Département de chimie moléculaire

The authors report the combination of latex nanosphere lithog. with electropolymn. of N-substituted pyrrole monomer bearing a nitrilotriacetic acid (NTA) moiety for the template-assisted nanostructuration of poly(pyrrole-NTA) films and their application for biomol. immobilization. The electrodes were modified by casting latex beads (100 or 900 nm in diam.) on their surface followed by electropolymn. of the pyrrole-NTA monomer and the subsequent chelation of Cu2+ ions. The dissoln. of the nanobeads leads then to a nanostructured polymer film with increased surface. Thanks to the versatile affinity interactions between the (NTA)Cu2+ complex and histidine- or biotin-tagged proteins, both tyrosinase and glucose oxidase were immobilized on the modified electrode. Nanostructuration of the polypyrrole via nanosphere lithog. (NSL) using 900- and 100-nm latex beads allows an increase in surface concn. of enzymes anchored on the functionalized polypyrrole electrode. The nanostructured enzyme electrodes were characterized by fluorescence microscopy, 3D laser scanning confocal microscopy, and SEM. Electrochem. studies demonstrate the increase in the amt. of immobilized biomols. and assocd. biosensor performances when achieving NSL compared to conventional polymer formation without bead template. In addn., the decrease in nanobead diam. from 900 to 100 nm provides an enhancement in biosensor performance. Between biosensors based on films polymd. without nanobeads and with 100-nm nanobeads, max. c.d. values increase from 4 to 56 $μ$A cm-2 and from 7 to 45 $μ$A cm-2 for biosensors based on tyrosinase and glucose oxidase, resp. [on SciFinder(R)]