Studies on the Development of Microelectrodes and Miniaturized Biosensors with A Novel Material: Petroleum Pitch-Based Carbon Fiber

Abstract

This article reports the experimental results of the studies of a carbon fiber microelectrode and therefore a miniaturized biosensor. The important progress that resulted from the use of oxidation pretreated petroleum pitch-based carbon fiber (PPCF) is described. The pretreatment on the PPCF microelectrode resulted in obvious improvement of its properties. The peak-shaped voltammograms are similar to that of a common-sized electrode, and the currents are higher than the nonpretreated one for several (even tens) folds due to the high dense surficial active centers as oxo acid and peroxide acid. The thionine is easily polymerized on the pretreated PPCF microelectrode, and as a matrix electrode, a miniaturized amperometric biosensor for catechol was developed by immobilization of a mushroom extract on it. The resulting biosensor could be applied to determine the catechol with a linear range of 1.0 × 10−7–1.0 × 10−5 mol/L and response time less than 50 s.