Different types of polymeric films implemented in various capacities i
n amperometric biosensor design are reviewed. Conducting and nonconduc
ting polymer films and composite films are considered. Methods of film
fabrication such as solvent casting, electropolymerization, and adsor
ption are presented. Film function, including prevention of interferen
ce and fouling problems, immobilization of the enzyme or active biocom
ponent, extension of linear range, or to address biocompatibility prob
lems are described. The use of polymeric films as a medium to incorpor
ate mediators, while an important function, is too vast for review her
e. The applications of polymer film-modified biosensors for selected a
nalytical determinations are also presented. This review focuses upon
the use of polymer films in amperometric biosensors and emphasizes inn
ovative biosensor designs and unique applications, and omits tradition
al free-standing films unless they are coupled with new types of polym
er films or used innovatively.