Facile fabrication of carboxyl groups modified fluorescent C60 through a one-step thiol-ene click reaction and their potential applications for biological imaging and intracellular drug delivery

Recently, fullerene (C 60 ) and its derivatives have attracted tremendous research interest in diverse fields owing to their excellent fluorescence and biological properties. In this work, the carboxyl groups containing fluorescent C 60 COOH nanoparticles have been prepared via a one-step thiol-ene click reaction for the first time. Then, we would further demonstrate that C 60 COOH nanoparticles possess excellent water dispersibility, low cytotoxicity, outstanding fluorescence properties and uniform minuscule based on various characterization techniques. On account of these advantages, we further evaluate their performance in cell imaging. Furthermore, the carboxyl groups on the surface of C 60 COOH nanoparticles could not only improve their water dispersibility, but also be potentially used to conjugate with various biomolecules and drug molecules. Based on these carboxyl groups, we loaded the anticancer agent cisplatin on C 60 COOH nanoparticles and further explore their potential for controlled drug release. Taken together, we have developed a novel thiol-ene click reaction for preparation of carboxyl groups functionalized fluorescent C 60 based nanoparticles, which showed great potential for biological imaging and potential for intracellular controlled drug delivery. More importantly, this strategy developed in this work should also be expanded for fabrication of other fluorescent C 60 based nanoparticles through utilizing different thiol-containing compounds and other fluorescent carbon nanoparticles. Therefore, this work will provide some novel ideas for the preparation of various fluorescent carbon nanoparticles for theranostic applications.