Zheng Ming, Jagota Anand, Strano Michael S, Santos Adelina P, Barone Paul, Chou S Grace, Diner Bruce A, Dresselhaus Mildred S, McLean Robert S, Onoa G Bibiana, Samsonidze Georgii G, Semke Ellen D, Usrey Monica, Walls Dennis J
DuPont Central Research and Development, Experimental Station, Wilmington, DE 19880, USA.
Science. 2003 Nov 28;302(5650):1545-8. doi: 10.1126/science.1091911.
Wrapping of carbon nanotubes (CNTs) by single-stranded DNA (ssDNA) was found to be sequence-dependent. A systematic search of the ssDNA library selected a sequence d(GT)n, n = 10 to 45 that self-assembles into a helical structure around individual nanotubes in such a way that the electrostatics of the DNA-CNT hybrid depends on tube diameter and electronic properties, enabling nanotube separation by anion exchange chromatography. Optical absorption and Raman spectroscopy show that early fractions are enriched in the smaller diameter and metallic tubes, whereas late fractions are enriched in the larger diameter and semiconducting tubes.
研究发现，单链DNA（ssDNA）对碳纳米管（CNT）的包裹具有序列依赖性。对ssDNA文库进行系统搜索后，选择了序列d(GT)n，其中n = 10至45，该序列能围绕单个纳米管自组装成螺旋结构，使得DNA-CNT杂合体的静电作用取决于管径和电子性质，从而能够通过阴离子交换色谱法分离纳米管。光吸收和拉曼光谱表明，较早的馏分富含较小直径的金属管，而较晚的馏分富含较大直径的半导体管。
