writer：Huaihong Zhan, Rong Huang, Hui Cang, Zhaosheng Cai and Baiwang Sun*
keywords：Graphene oxide–coumarin derivative
source：期刊
specific source：Journal of Materials Chemistry B
Issue time：2014年
An interesting activatable ?uorescent imaging probe based on a graphene oxide–coumarin derivative conjugate with high sensitivity in cancer cell visualization was proposed. The nanoprobe has  a ?uorescence o?–on response for intracellular imaging via covalently linking coumarin derivatives to graphene oxide (GO) through disul?de bonds. The obtained nanoprobe shows no or weak ?uorescence (OFF) most likely due to the ?uorescence resonance energy transfer from the coumarin moiety to GO. It becomes activated (ON) inside the cells by glutathione initiated dissociation, showing remarkably enhanced ?uorescence. More signi?cantly, the present activatable nanoprobe can be e?ciently taken up by cells. Two-photon induced ?uorescence imaging of the proposed nanoprobe was also clearly observed by utilizing femtosecond pulse laser excitation, and a?ords a powerful alternative candidate for near-infrared (NIR) ?uorescence imaging of tumors. Similar ?uorescence was visualized in a tumor- bearing mouse model using this probe. These results demonstrate the potential of using this activatable nanoprobe for the detection of cancer.