Dispersant-dependence of the resonance Raman spectra and excitation profiles for aqueous SWCNT solutions
Rachel Stephenson1, Ashwinkumar Bhirde2, Constantine Khripin3, Xiaoyuan Chen2, Jeffery Fagan3, Ming Zhang3, Angela Hight Walker1
1National Institute for Standards and Technology, Radiation and Biomolecular Physics Division, Gaithersburg, MD 20899
2National Institute for Biomedical Imaging and Bioengineering, Laboratory of Molecular Imaging and Nanomedicine, Bethesda, MD 20892
3National Institute for Standards and Technology, Polymers Division, Gaithersburg, MD 20899
Single-wall carbon nanotubes (SWCNTs) are well known for their unique mechanical, electronic and optical properties; properties which are dependent on the SWCNT chirality, length and especially local environment. Recently, SWCNTs have received attention as components in nanomedicine applications, because they can be modified to include targeting or therapeutic agents, and because they can be observed once uptaken by cells due to the strong resonance Raman and/or fluorescence signal. However, as the SWCNT properties are strongly influenced by their environment, a detailed spectral analysis is necessary to ensure comparability between studies and technical quality. In this work, we show the dispersant dependence of the resonance Raman spectra and excitation profiles for commercially available SWCNTs dispersed using several bio-compatible dispersants. Other characterization methods will include optical absorbance and photoluminescence. Items to consider when designing an in vivo, in vitro or toxicity study around the resonance Raman signal from the SWCNTs will be highlighted.