The electrochemical behavior of hydrogen peroxide (H2O2) at nanoporous platinum (Pt) thin film was investigated and the reaction of the enzymes immobilized on the electrode was examined. The nanoporous Pt underlying the enzyme layer was electrochemically deposited on Pt-Ir alloy microelectrodes in the solution consisting of hexachloroplatinic acid and a non-ionic surfactant, octaethylene glycol monohexadecyl ether (C16EO8). Glutamate oxidases were entrapped during electro-polymerization of 1,3-phenylenediamineon the nanoporous Pt microelectrodes to form a glutamate oxidase layer. The glutamate microsensors as made were compared with flat Pt-based one in terms of the performance and characteristics. (c) 2006 Elsevier Ltd. All rights reserved.