Green and High-Efficiency Reduction of Graphene Oxide for Highly Loading Drug to Enhance Cancer Therapy

Graphene oxide (GO) can be reduced by various approaches, but it is still a great challenge to find an eco-friendly and low energy consuming method to reduce it. We in this work for the first time proposed use of high pressure vapor sterilization as a totally green and high-efficiency method for preparing reduced graphene oxide (rGO). The effects of vapor temperature and pressure, pH value and reduction time on reduction extent were also investigated. After characterization by UV-vis, FTIR, XPS, XRD and TG, we found that the use of high pressure vapor could reduce the GO within 2 h in a highly efficient manner and the high pressure vapor played an irreplaceable role. The results showed that the C/O ratio was as high as 8.73 in Na2HPO4 center dot 12H(2)O-NaOH buffer solution (pH 11.007) at 121 degrees C and 0.20 MPa. Since autoclave is the only apparatus for preparing rGO, this method is suitable for large-scale production of rGO. Meanwhile, the obtained high reduction degree of rGO was higher loading efficiency and anticancer effect than those of low reduction degree of rGO. In conclusion, high pressure vapor sterilization has great potential to be used as novel, efficient and totally green method for production of rGO. Moreover, the products are friendly to L929 cells at certain concentration and used as the drug carrier to enhance cancer therapy, which make them applicable in biomedicine fields.