Compositional Analysis of ssDNA-Coated Single-Wall Carbon Nanotubes through UV Absorption Spectroscopy
Compositional Analysis of ssDNA-Coated Single-Wall Carbon Nanotubes through UV Absorption Spectroscopy
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DOI：
10.1021/acs.nanolett.2c02850
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发表时间：
2022-10-26
期刊：
影响因子：
10.8
通讯作者：
Weisman, R. Bruce
中科院分区：
文献类型：
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作者：
Alizadehmojarad, Ali A.;Bachilo, Sergei M.;Weisman, R. Bruce
采用紫外吸收和总碳测量对单壁碳纳米管（SWCNTs）的水悬浮液进行了分析。结果给出了无游离ssDNA样品中两种组分的绝对平均浓度。根据这些值，推导出三个不同批次相对较小直径的纳米管（两个HiPco和一个CoMoCAT）的平均中紫外swcnts吸收率。吸收率值允许使用简单的分光光度法来测量水SDS中类似swcnts样品的绝对浓度。结果还量化了ssDNA与swcnts的质量比，定义了T15GT15或T30G的一条ssDNA链悬浮的纳米管碳原子的平均数量。将该实验参数与（6,5）片段上自由吸附的一条ssDNA链的复制交换分子动力学模拟结果进行比较，结果表明，计算得到的每条链上覆盖的swcnts原子数与测量到的每条链悬浮的swcnts原子数非常吻合。
Aqueous suspensions of single-wall carbon nanotubes (SWCNTs) coated by ssDNA are analyzed using UV absorption and total carbon measurements. The results give absolute average concen-trations of both components in samples without free ssDNA. From those values, the average mid-UV SWCNT absorptivity is deduced for three different batches of relatively small diameter nanotubes: two HiPco and one CoMoCAT. The absorptivity values enable the use of simple spectropho-tometry to measure absolute concentrations of similar SWCNT samples in aqueous SDS. The results also quantify the mass ratio of ssDNA to SWCNT, defining the average number of nanotube carbon atoms suspended by one ssDNA strand of T15GT15 or T30G. Comparing this experimental parameter with results from replica exchange molecular dynamics simulations of one ssDNA strand freely adsorbed on a (6,5) segment shows close agreement between the computed number of SWCNT atoms covered per strand and the measured number of SWCNT atoms suspended per strand.