Modification of Disposable Screen-Printed Carbon Electrode Surfaces with Conductive Electrospun Nanofibers for Biosensor Applications

In this work, we describe an alternative approach to the surface modification of screen-printed carbon electrodes (SPCEs) to fabricate a polypyrrole/polyacrylonitrile multiwall carbon nanotube-modified screen-printed carbon electrode (PPy/PAN-MWCNT/SPCE) using a two-step process. First, PAN loaded with 5 wt % of MWCNTs was electrospun onto a carbon layer. The CNT-embedded PAN electrospun nanofibers (average diameter approximate to 200 nm) were subsequently coated with a PPy layer via vapor-phase polymerization using p-toluenesulfonate as an oxidizing agent in a vacuum system. The electrochemical behavior of both the unmodified and the modified SPCEs were compared using cyclic voltammetry (CV) with common electroactive analytes in order to optimize the electrospinning and the vapor-phase parameters. By incorporating glucose oxidase(GOX) as an enzymatic model into the modified electrode without a mediator, we conducted a calibration study which showed that glucose could be detected by an amperometer over a linear range of 0.25-6 mM with a LOD of 15.51 M and a sensitivity of 5.41 A/mM cm(2). With a mediator, the glucose detection can be performed at low potential over a linear range of 0.125-7 mM with a LOD of 0.98 mM and a sensitivity of 14.62 A/mM cm(2). Therefore, the novel modified electrode is a promising new device for biosensor applications. (c) 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3885-3893, 2013