Absorption spectroscopic study of DNA hybridization using single-walled carbon nanotubes

Single walled carbon nanotubes show pronounced sharp UV-vis-NIR absorption peak distributions while they are individually dispersed in aqueous solution phase. In this paper, we present optical absorbance detection of DNA hybridization using developed ssDNA-SWNT conjugates. Hybridization of DNA oligonucleotides with their complementary sequences makes systematic red shifts of linked nanotubes in the near infrared region. Semiconducting tubes exhibit clear responses whereas metallic species do not. The results show that SWNTs may be used to selectively detect specific kinds of DNA oligonucleotides.