Mussel-inspired preparation of C60 nanoparticles as photo-driven DNA cleavage reagents

Designing and constructing favorable water-dispersible fullerenes and their derivatives are of huge importance for biological applications addressing DNA-cleavage and photodynamic therapy (PDT). In the present work, a mild, green and facile synthetic approach for the preparation of C60 nanoparticles was developed for the first time via the combination of mussel-inspired chemistry and the Michael addition reaction. The resultant C60–PDA–PEI nanoparticles were characterized by transmission electron microscopy (TEM), dynamic laser scattering (DLS), Fourier-transform infrared spectroscopy (FT-IR), Raman spectra, X-ray photoelectron spectra (XPS) and thermogravimetric analysis (TGA), demonstrating that the above two-step strategy allows easy access to the preparation of highly water-dispersible fullerene derivatives. Benefiting from their unique nanostructure, the versatile C60–PDA–PEI nanoparticles display a uniform hydrodynamic size of 160 nm in water and efficient 1O2 generation under irradiation. Furthermore, the good ability of cleaving DNA under visible light at a mass concentration of 62.5 ng μL−1 gives them high potential as PDT agents. The universal approach described in this work is capable of introducing many other functional molecules onto PDA-modified fullerenes, thus extending the possible applications of fullerene-based species in many fields of biotechnology and pharmaceutical chemistry.