Luminescence in laser-generated functionalized carbon dots

Abstract

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 μm 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.