Design and synthesis of highly fluorescent and stable fullerene nanoparticles as probes for folic acid detection and targeted cancer cell imaging

Rational design and construction of fullerene derivatives play significant roles in the development of applications for sensing, marking and imaging in biomedical fields. In the present work, a novel type of C-60 fluorescent nanoparticle (C-60 FNP) was synthesized by a combination of thiol-ene chemistry and modification with folic acid (FA). The as-prepared C-60 FNPs exhibited intense blue luminescence with a relatively high quantum yield of 26%, which is higher than that of any other reported fluorescent fullerene-based nanomaterial. Moreover, they revealed superior photobleaching resistance under constant UV lamp illumination for 5 h and excellent photostablity after 9 months of storage in water. Due to the mutual hydrogen bond interaction, the obtained C-60 FNPs were capable of acting as a sensitive and specific probe for FA detection and quantification, with a liner range of 0 to 80 mu M and a detection limit of 0.24 mu M. Satisfactory recoveries (95.4%-105.2%) were obtained from a series of actual samples, further confirming the feasibility of this nanoprobe. Additionally, taking advantage of the FA moiety, the C-60 FNPs had easy access to penetrate into cancer cells with higher expression levels of folate receptors, thereby achieving the function of targeted cellular imaging.

Automated summary

A novel type of C-60 fluorescent nanoparticle with high quantum yield and excellent photostability was synthesized in this study, serving as a sensitive probe for folic acid detection and quantification. Moreover, these nanoparticles could penetrate into cancer cells with higher expression levels of folate receptors, achieving targeted cellular imaging.