DNA entrapped polypyrrole-polyvinyl sulfonate film for application to electrochemical biosensor.

Double-stranded calf thymus (dsCT)-DNA was electrochemically entrapped into polypyrrole-polyvinyl sulfonate (PPy-PVS) films deposited onto indium tin oxide (ITO) coated glass plates. These dsCT-DNA entrapped PPy-PVS/ITO films were characterized using cyclic voltammetry, UV-visible, Fourier transform infrared (FT-IR), scanning tunneling microscopy (STM), and electrochemical impedance measurements. Attempts made to use these dsCT-DNA entrapped PPy-PVS/ITO films for detection of 2-aminoanthracene (0.001-6.0 ppm) and 3-chlorophenol (0.01-55.0 ppm) revealed a response time of 30s and a shelf life of approximately 25 weeks when stored under desiccated conditions at 25 degrees C. The addition of salts such as Ca(2+) (250 ppm), Mg(2+) (200 ppm), Cl(-) (1560 ppm), and Na(+) (150 ppm) ions contained in water does not affect the observed amperometric response of the disposable dsCT-DNA entrapped PPy-PVS film-based electrochemical biosensor.