Tomura Akihiro, Umemura Kazuo
Biophysics Section, Department of Physics, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo, 162-8601, Japan.
Anal Biochem. 2018 Apr 15;547:1-6. doi: 10.1016/j.ab.2018.02.004. Epub 2018 Feb 8.
We demonstrated the attachment of different kinds of dyes, Uranine, Rhodamime 800 (R800), and Indocyanine green (ICG), to single-walled carbon nanotubes pre-wrapped with single-stranded DNAs (ssDNA-SWCNTs). A new but simple method was employed, in which a dye solution was added to ssDNA-SWCNTs that had been prepared beforehand in the conventional way. Resulting conjugates of dyes, DNA, and SWCNTs were precisely evaluated by ultraviolet to near-infrared fluorescence/absorbance spectrometry and atomic force microscopy. In particular, simultaneous measurements of fluorescence and absorbance spectroscopy enabled us to find differences in the behaviors of the dyes on SWCNT surfaces. As a result, the fluorescence/absorbance spectra of dyes showed significant changes upon adsorption on SWCNTs. The fluorescence/absorbance peaks of Uranine, R800, and ICG were quenched by 41.3/2.8%, 72.3/48.9%, and 88.3/45.0%, respectively, in the presence of 11.5 μg/mL SWCNTs. We concluded firstly that by pre-wrapping SWCNTs with ssDNA, stable hybrids with these components were obtained even if the dyes used were relatively hydrophobic and secondly that Uranine retained light absorption on the surface of SWCNT while R800 and ICG did not.
我们展示了将不同种类的染料，即铀试剂、罗丹明800（R800）和吲哚菁绿（ICG），附着到预先用单链DNA包裹的单壁碳纳米管（ssDNA - SWCNTs）上。采用了一种新的但简单的方法，即将染料溶液添加到以传统方式预先制备好的ssDNA - SWCNTs中。通过紫外到近红外荧光/吸光光谱法和原子力显微镜对所得的染料、DNA和SWCNT的共轭物进行了精确评估。特别是，荧光和吸光光谱的同步测量使我们能够发现染料在SWCNT表面行为的差异。结果，染料的荧光/吸光光谱在吸附到SWCNTs上时显示出显著变化。在存在11.5μg/mL SWCNTs的情况下，铀试剂、R800和ICG的荧光/吸光峰分别猝灭了41.3/2.8%、72.3/48.9%和88.3/45.0%。我们首先得出结论，通过用ssDNA预先包裹SWCNTs，即使所用的染料相对疏水，也能获得这些成分的稳定杂化物；其次得出结论，铀试剂在SWCNT表面保留了光吸收，而R800和ICG则没有。
