Nanotechnology presents a very fast growth owing to a vast number of applications. In medicine, for example, it is possible to envisage a strong improvement in the efficiency of the magnetic resonance imaging or in the development of non-conventional diagnostics or therapies. The pace of development of the area is strongly dependent on the improvement of synthesis routes, which would allow producing, in a controlled way, new materials capable to act in the intracellular environment.

Infections and several diseases caused by resistant micro-organisms in which the conventional treatment often fails result in prolonged illness and greater risks of death. The inappropriate and irrational use of antibiotics and antimicrobial drugs can lead to resistant microorganisms and provide them with favorable conditions to emerge, spread, and persist. According to the World Health Organization (WHO), a high percentage of hospital-acquired infections are caused by highly resistant bacteria and 440 000 new cases of multidrug-resistant tuberculosis emerge annually, causing at least 150 000 deaths.

Lanthanide-containing materials comprise a wide range of scientifically and technologically important compounds. They are chemically designed and produced by using different routes depending on the final target: single crystals, glasses, organic-inorganic hybrids, and ceramics. A huge variety of properties can be obtained depending on the choice of the lanthanide, the host matrices and crystalline structures in which they are inserted, either as a dopant or as self-activated element. Known for possessing rich luminescence properties, lanthanides-containing materials have been used in many technological applications, such as laser materials, flat panel displays, cathode ray tubes, up-conversion devices, white-light emitting diodes, X-Ray scintillators, phosphors, and emitters.

Silver nanoparticles have an antibacterial effect and therefore have potential biomedical applications. Bacteriological tests have revealed that this effect depends on the size of the nanoparticles and the type of microorganism. The challenge consists in performing selective fractionation to identify the most effective nanoparticles for each type of microorganism.