Fabrication and Deposition of Copper and Copper Oxide Nanoparticles by Laser Ablation in Open Air

The proximity of the "post-antibiotic era", where infections and minor injuries could be a cause of death, there are urges to seek an alternative for the cure of infectious diseases. Copper nanoparticles and their huge potential as a bactericidal agent could be a solution. In this work, Cu and Cu oxide nanoparticles were synthesized by laser ablation in open air and in argon atmosphere using 532 and 1064 nm radiation generated by nanosecond and picosecond Nd:YVO₄ lasers, respectively, to be directly deposited onto Ti substrates. Size, morphology, composition and the crystalline structure of the produced nanoparticles have been studied by the means of field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), the energy dispersive spectroscopy of X-rays (EDS), selected area electron diffraction (SAED) and X-ray diffraction (XRD). The UV-VIS absorbance of the thin layer of nanoparticles was also measured, and the antibacterial capacity of the obtained deposits tested against Staphylococcus aureus. The obtained deposits consisted of porous coatings composed of copper and copper oxide nanoparticles interconnected to form chain-like aggregates. The use of the argon atmosphere contributed to reduce significantly the formation of Cu oxide species. The synthesized and deposited nanoparticles exhibited an inhibitory effect upon S. aureus.