casting, electropolymerization, and adsorption. Belanger et al.
electropolymerized a conducting glucose oxidase/polypyrrole film
onto the Pt disk of a rotating ring-disk electrode to fabricate a
glucose sensor [13]. Yacynych et al. evaluated the effectiveness
of various electropolymerized films and reported that poly(1,3-
phenylenediamine/resorcinol) film covered electrode was not
fouled by serum solution. In that work, glucose oxidase (GOD)
was immobilized onto the electrode surface by crosslinking with
glutaraldehyde followed by an electropolymerized film, and the
resulted sensor had a linear response (2.5–10 mm) using FIA
method [14]. In the present work, we simultaneously immobilized
GOD into the interspace of poly(1,3-phenylenediamine/resorcinol)
molecules during electropolymerization followed by modification
of Nafion perfluorinated ion exchange resin (5 wt.% solution in
lower aliphatic alcohols/H2O mix containing 45% water) film. A
wider linear range of 0.1–50 mM for serum glucose detection was
achieved in FIA system, and such configuration of glucose sensor
and so wide linear range for detection have rarely been reported
by now.