Various responses of single-walled carbon nanotubes with differing chirality: A suggestion for biosensing

The near infrared absorbance and near infrared photoluminescence intensity of several single-walled carbon nanotubes (SWNTs) with different chiralities in the same suspension were analyzed. Differing chirality of the SWNTs showed different spectral responses with adsorbed H2O2 and catechin. While the detection of the antioxidant effects of catechin and Japanese tea using hybrids of DNA and SWNTs have previously been reported, those studies did not focus on the effects of chirality of the SWNTs on near infrared spectra. Chirality of SWNTs is one of the most important parameters to determine SWNT physicochemical properties. For example, the responses of (10,5)/(8,7) were more drastic in contrast to (9,4), while the (6,5) SWNTs were inactive. The findings indicate that different information can be obtained using mixed chiralities of SWNTs. The data suggest that the chirality effects reported from various studies should be evaluated carefully, considering the different SWNT chiralities.