Graphene Oxide Assisted Fluorescent Chemodosimeter for High-Performance Sensing and Bioimaging of Fluoride Ions

Fluorescent chemodosimeters for a fluoride ion (F(-)) based on a specifically F(-)-triggered chemical reaction are characterized by high selectivity. However, they are also subjected to intrinsic limits, such as long response time, poor stability under aqueous solution, and unpredictable cell-member penetration. To address these issues, we reported here that the self-assembly of fluorescent chemodosimeter molecules on a graphene oxide (GO) surface can solve these problems by taking advantage of the excellent chemical catalysis and nanocarrier functions of GO. As a proof of concept, a new F(-)-specific fluorescent chemodosimeter molecule, FC-A, and the GO self-assembly structure of GO/FC-A were synthesized and characterized. Fluorescent sensing and imaging of F(-) with FC-A and GO/FC-A were performed. The results showed that the reaction rate constant of GO/FC-A for F(-) is about 5-fold larger than that of FC-A, so that the response time was shortened from 4 h to about 30 min, while for F(-), the response sensitivity of GO/FC-A was >2-fold higher than that of FC-A. Furthermore, GO/FC-A showed a better bioimaging performance for F(-) than FC-A because of the nanocarrier function of GO for cells. It is demonstrated that this GO-based strategy is feasible and general, which could help in the exploration of the development of more effective fluorescent nanodosimeters for other analytes of interest.