Sodium Carboxyl Methyl Cellulose for Improvement of the Determination of Polyethylene Glycol Modified Carbon Nanotubes by Raman Spectroscopy

Abstract

Single-walled carbon nanotubes (SWNTs) have shown great potential in various areas of biomedicine. However, few research studies have focused on in vivo carbon nanotube detection by Raman spectroscopy. In this work, SWNTs were functionalized with polyethylene glycol (PEG) to form PEG-o-SWNTs to improve the biocompatibility and dispersibility. A novel application of Raman scattering was used to detect the PEG-o-SWNTs. Compared to the traditional assay method, the recovery rate was improved from 84.2% to 102.7%, the correlation coefficient of the standard curve increased from 0.7315 to 0.9872, and the degree of precision decreased from 4.4% to 3.1%. Large errors in the measured results were found the cryopreserved blood and organ samples in which the reticular sediments separated, on which the nanotubes generally concentrate. It was determined that by achieving a final concentration of 0.5% through the addition of sodium carboxyl methyl cellulose (CMC-Na), the homogeneity of the tested sample can be greatly enhanced, thus boosting the accuracy of the analyses. This work offers methods with higher accuracy for determining the presence of PEG-o-SWNTs in blood and organs using Raman spectroscopy.

Keywords:

• Carbon nanotube
• Raman spectroscopy
• Sodium carboxyl methyl cellulose

Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant No. 30960515), the Foundation from Shihezi University (ZRKXYB-13, YX07010), the Doctor Foundation of Corps (No. 2012BB020), and the High-level Personnel Foundation of Shihezi University (No. RCZX201115).

Notes

*The spectra of blank sample of both methods have no peak between 1550 and 1650 cm⁻¹.