Preparation and spectra of (13)~C-enriched fullerene

In the last three decades, due to the unique structure and biological activities of fullerene materials, many reports were published on their synthesis and application in biomedical and environmental sciences, however, there is very few examples that have leapt out of the laboratory and into the commercial market. Obviously, further study is required to solve their crucial biological safety issues. In this article, the 13C-C60 sample was synthesized by arc discharge method with the stable isotope 13C direct substituting the skeleton carbon atoms on the carbon cage. The numbers of the incorporated 13C-atoms have been identified by isotope ratio mass spectroscopy. The isotope effect of the skeleton 13C-enriched C60 made its mass spectrum and vibrational Infrared/Raman spectra changes. Its mass spectra peaks at range from m/z=719~734 showed the normal distribution and the strongest peak position shifted up with the increase number of 13C. Infrared and Raman spectra of 13C-C60 retained the characteristic spectrum of C60, however, due to the stable isotope 13C-incorporated reducing C60 molecular symmetry, the characteristic peaks occurred the migration and splitting with increasing the number of 13C. Simultaneously, the 13C direct labeling method does not destroy the intrinsic structure of fullerene. Undoubtedly, 13C-C60 will open the door for quantitatively, safely and non-destructively evaluating on the biological safety of fullerene nanomaterials in vivo.