Fabrication of Porous Pseudo-Carbon Paste Electrode as a Novel High-Sensitive Electrochemical Biosensor

Abstract

Porous pseudo-carbon paste electrode (PPCPE) as a novel high-sensitive electrochemical biosensor was fabricated by mixing polymethyl methacrylate (PMMA) microspheres for use as the template, graphite powders for the filler, and pyrrole as the precursor of the polymer which acted as the paste. After the polymerization of pyrrole catalyzed by Fe³⁺, the PMMA microspheres were removed to form PPCPE. The pore size was determined by SEM observations, with diameters ranging from 2 to 5 µm. The anodic stripping voltammetry response of DNA indicated that the adsorption of oligonucleotide on PPCPE was enhanced. The PPCPE was easy to preserve and had a good reusability in comparison with that of a pure carbon paste electrode (CPE) and a carbon nanotube-modified carbon paste electrode (CNTPE). The detection limits of guanine and adenine were 20 nM and 8 nM, respectively.

Keywords:

• Carbon nanotube modified carbon paste electrode
• electrochemical biosensor
• porous pseudo-carbon paste electrode
• specific surface area

This research is financially supported by the National Natural Science Foundation (NO. 60571032, 90606027, 60121101), the 863 High Tech Project (NO. 2007AA022007), the Hunan Science and Technology Project (2007FJ4050), the Doctoral Program of Higher Education for Funding of China (NO. 20050286014) and Scientific Research Fund of Hunan Provincial Education Department (08C294).