Luminescence in laser-generated functionalized carbon dots

Biocompatible carbon dots (CDs) were obtained by the laser ablation of vegetable carbon in phosphate-buffered saline (PBS) solution. The carbon nanoparticles were generated by an IR laser beam at a 970 nm wavelength with a spot of 200 mu m diameter, pulse of 100 ms and of 350 mJ energy, at a 10 Hz repetition rate. The ablation rate, in terms of removed carbon mass per laser shot, was evaluated to be about 5.3 ng. UV - Vis spectroscopy and luminescence measurements were employed to evince the CDs luminescence. The UV excitation at a 365 nm wavelength induces CDs luminescence mainly at about 478 nm and 518 nm giving to the emitted light a characteristic blue-green color. The CDs luminescence in biocompatible solutions is presented and discussed as possible applications to the bio -medical field.