DNA-modified screen-printed electrodes with nanostructured films of multiwall carbon nanotubes, hydroxyapatite and montmorillonite

Nanostructured films, were deposited at the surface of working electrode of the screen-printed assembly and utilized for the surface modification with double-stranded DNA. The basic electrochemical properties of the sensors were investigated using voltammetric methods. Modified electrodes were also characterized by scanning electron microscopy and electrochemical impedance measurements. It was found that the electrode modification with DNA and nanomodifier leads to in enhanced sensitivity of the DNA voltammetric detection. New potentialities of the utilization of the K-3[Fe(CN)(6)] cyclic voltammetric signal and electrochemical impedance spectroscopy were found. The DNA-based biosensors showed good repeability and necessary stability within several days.