Department of Chemistry and the Smalley-Curl Institute, Rice University, Houston, Texas 77005, United States.
Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, United States.
Nano Lett. 2022 Oct 26;22(20):8203-8209. doi: 10.1021/acs.nanolett.2c02850. Epub 2022 Oct 6.
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 concentrations 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 spectrophotometry 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 TGT or TG. 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.
采用紫外吸收和总碳测量法对 ssDNA 包裹的单壁碳纳米管（SWCNT）的水悬浮液进行分析。结果给出了无游离 ssDNA 样品中两种成分的绝对平均浓度。根据这些值，推导出了三种相对较小直径的纳米管的中紫外 SWCNT 吸光度：两个 HiPco 和一个 CoMoCAT。吸光度值使得可以使用简单的分光光度法测量 SDS 中类似 SWCNT 样品的绝对浓度。结果还量化了 ssDNA 与 SWCNT 的质量比，定义了由一个 TGT 或 TG 的 ssDNA 链悬浮的 SWCNT 碳原子的平均数量。将这个实验参数与 ssDNA 链自由吸附在（6,5）段上的 replica exchange 分子动力学模拟的结果进行比较，表明计算出的每个链覆盖的 SWCNT 原子数与测量出的每个链悬浮的 SWCNT 原子数之间非常吻合。
