Department of Chemistry and Richard E. Smalley Institute for Nanoscale Science and Technology, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
Anal Chem. 2011 Oct 1;83(19):7431-7. doi: 10.1021/ac2014788. Epub 2011 Sep 9.
A new method and instrumentation are described for rapid compositional analysis of single-walled carbon nanotube (SWCNT) samples. The customized optical system uses multiple fixed-wavelength lasers to excite NIR fluorescence from SWCNTs individualized in aqueous suspensions. The emission spectra are efficiently captured by a NIR spectrometer with InGaAs multichannel detector and then analyzed by a computer program that consults a database of SWCNT spectral parameters. The identities and relative abundances of semiconducting SWCNTs species are quickly deduced and displayed in graphs and tables. Results are found to be consistent with those based on manual interpretation of full excitation-emission scans from a conventional spectrofluorometer. The new instrument also measures absorption spectra using a broadband lamp and multichannel spectrometers, allowing samples to be automatically characterized by their emission efficiencies. The system provides rapid data acquisition and is sensitive enough to detect the fluorescence of a few picograms of SWCNTs in ~50 μL sample volumes.
描述了一种用于快速分析单壁碳纳米管（SWCNT）样品成分的新方法和仪器。定制的光学系统使用多个固定波长的激光器来激发水溶液中分离的 SWCNT 的近红外荧光。发射光谱由带有 InGaAs 多通道探测器的近红外光谱仪有效捕获，然后由计算机程序进行分析，该程序会参考 SWCNT 光谱参数数据库。可以快速推断出半导体 SWCNT 种类的身份和相对丰度，并以图表和表格的形式显示结果。结果与基于传统荧光光谱仪的全激发-发射扫描的手动解释结果一致。新仪器还使用宽带灯和多通道光谱仪测量吸收光谱，允许通过发射效率自动对样品进行表征。该系统提供快速的数据采集，并且足够灵敏，可以检测到约 50 μL 样品体积中几个皮克 SWCNT 的荧光。
