Porous Magnetic Pseudo-Carbon Paste Electrode Electrochemical Biosensor for DNA Detection.

A novel and sensitive electrochemical sensor based on magnetic porous pseudo-carbon paste electrode (MPPCPE) for DNA detection was described in this study. The MPPCPE was fabricated by mixing polymethyl methacrylate (PMMA) microspheres, as template, graphite powders, as filler, pyrrole, as precursor of polymer and magnetic powder. It was demonstrated that the fabricated MPPCPE had more sensitivity for detecting DNA when compared with magnetic carbon paste electrode (MPCPE). Results from anodic stripping voltammetry (ASV) experiments showed that the Ag peak current versus concentration of complementary DNA at MPPCPE had two linear regions. The first region demonstrated linearity over a concentration range from 0.5 to 20 nM, with correlation coefficient of 0.992, while the second linear region had concentration of complementary DNA at 0.005 to 0.1 nM range, with correlation coefficient of 0.957. The detection limit was as low as 0.005 nM and the electrochemical sensor was easy to preserve for a long time, and had good reusability and stability.