The user can prepare a sample in a few minutes by ultrasonically dispersing ca. 0.01 mg of a raw solid SWNT specimen into a small volume of aqueous surfactant solution. A few drops of this suspended specimen are then placed into the NanoSpectralyzer’s sample cell. After simple selection of experimental modes, a single mouse-click launches an automated sequence of data collection and interpretation that quickly provides the operator with a detailed compositional analysis. The sample is first irradiated with light from diode lasers of pre-selected wavelengths, and the resulting fluorescence emission is collected by specialized optics, dispersed in a spectrograph, detected by a multichannel near-IR sensor, and recorded by the instrument’s computer. The resulting spectral data are automatically analyzed, using established findings in SWNT optical spectroscopy, to provide a detailed description of the semiconducting SWNT content of the sample. Specific (n,m) species are identified along with their apparent relative abundances. The findings are also displayed in the form of a diameter distribution.

NS1 NanoSpectralyzer optical schematic

In addition, the NanoSpectralyzer records near-infrared absorption spectra, which are automatically compared to emission data to characterize the sample purity in terms of unbundled and undamaged SWNT. The entire analysis process is typically completed within seconds. As an option, the wavelength range for absorption spectroscopy can be extended down to ~380 nm to capture transitions of metallic SWNT. The NanoSpectralyzer’s high level of automation allows it to be operated by non-specialists. Its compact, portable design requires less than 2 square feet of table or bench space.

Main control screen (larger view)

Applied NanoFluorescence is committed to providing its customers with software updates that will incorporate future research findings from the active area of SWNT spectroscopy and photophysics. So as further progress is made in understanding the basic optical properties of SWNTs, NanoSpectralyzer users always retain leading-edge analysis capabilities.