A carbon fiber microelectrode-based third-generation biosensor for superoxide anion

Implantable and miniature carbon fiber microelectrode (CFME)-based third-generation biosensor for superoxide anion (O-2(center dot-)) was fabricated for the first time. The CFME-based biosensor was constructed by electro-deposition of An nanoparticles on the CFMEs and then modification of the Au nanoparticles by cysteine followed by immobilization of superoxide dismutase (SOD) on the electrodes. The direct electrochemistry of the SOD immobilized on the CFME-based electrodes was efficiently realized by electron transfer promoter - cysteine molecules confined on the An nanoparticles deposited on the CFMEs. The CFME-based biosensors were demonstrated to possess striking analytical properties for O-2(center dot-) determination, such as optional operation potentials, high selectivity and sensitivity as well as good stability. Along with the implantable capacity inherent in the CFMEs, these striking analytical properties of the CFME-based biosensors substantially make them potential for in vivo determination of O-2(center dot-). (c) 2004 Elsevier B.V. All rights reserved.