Graphene oxide–coumarin derivative conjugate as activatable nanoprobe for intracellular imaging with one- or two-photon excitation

Graphene oxide–coumarin derivative conjugate as activatable nanoprobe for intracellular imaging with one- or two-photon excitation
来源：孙柏旺教授个人网站 2014-02-24

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.
[来源：中国聚合物网]