Random copolymers of poly(N-vinylcarbazole-styrene), P[NVCz-co-St], and poly(N-vinylcarbazole-acrylonitrile), P[NVCz-co-AN] were synthesized by the reaction of ceric ammonium nitrate (CAN) in acetonitrile. The resulting copolymers of P[NVCz-co-St], and P[NVCz-co-AN] were electrochemically coated (grafted) onto a few single carbon fiber microelectrodes. The electrocoated carbon fibers were characterized by cyclic voltammetry (CV), FT-IR-ATR, UV-Vis spectrophotometer, and scanning electron microscope (SEM). Polymer modified carbon fiber microelectrodes and platinum electrodes were tested and compared with respect to biosensor behavior (reversibility) against dopamine. (C) 2003 Elsevier B.V. All rights reserved.