Dye-enhanced graphene oxide for photothermal therapy and photoacoustic imaging

Graphene oxide (GO) has many exciting advantages such as easy preparation, low toxicity, good solubility and stability in aqueous solution. However, GO itself has a low near-infrared (NIR) absorption, and thus is not suitable for photothermal therapy and photoacoustic imaging. To overcome this limitation, a novel dye-enhanced GO is prepared utilizing the pi-pi stacking interactions between GO and indocyanine green (ICG). The ICG-GO complex has a high optical absorbance in the NIR region and exhibits excellent photothermal properties under NIR irradiation. In order to improve the cancer-targeting activity, GO was modified with folic acid (FA). In vitro experiments showed that the ICG-GO-FA nanocomposite could be used for targeted photothermal cancer cell destruction. Moreover, the application of the ICG-GO-FA nanocomposite for photoacoustic imaging was also demonstrated.