DNA-PDDA-CNT nanocomposites were fabricated by immobilizing DNA on the surface of single-walled carbon nanotubes (CNT) via poly(dimethyldiallylammonium chloride) (PDDA). The atomic force microscopy (AFM), ultraviolet-visible (UV-Vis), Raman spectroscopy and impedance spectroscopy (EIS) were used to characterize the growth processes of the nanocomposites. The cyclic voltammetric results indicate that the interaction between 1-phenylazo-2-naphthol (PN) and the immobilized DNA is intercalative binding, and PN can be used as a probe for detection of DNA damage. PN seems to be an attractive probe for DNA damage analysis since its redox peak is at ca. 0.1 V (vs. SCE, pH 5.5), where interference should be minimal.

Key words: carbon nanotube, DNA, DNA damage, electrochemical detection