2, CNYN, Universidad Nacional Autónoma de México (UNAM), Ensenada, Baja California, Mexico
3, CNYN, Universidad Nacional Autónoma de México (UNAM), Ensenada, Baja California, Mexico
The upconversion nanoparticles (UCNPs) have applications in the biomedical industry, they can function as specific cell targets, either to identify them or to deliver drugs, especially in cancer cells thar can be differentiated from healthy cells. In this study, we synthesize with the sol-gel technique, UCNPs with excellent luminescent properties such as La2O3 codoped with Er3 + and Yb3 + and Y2O3 codoped with Yb3 +, Ho3 + and Er3 + which present luminescence in the green (λ= 550 nm ) and red ( λ=660 nm) range. The upconversion process consists of the fact that the Yb3 + ion absorbs a photon with a wavelength of 980 nm and transfers the energy to the activating ion that can be Er3 + or Ho3 +, the electron returning to its base state emits in the visible spectrum. The functionalization with aminosilanes consists of two stages: first is a coating of silica in the nanoparticles, to make them inert in biological components and the second part is to functionalize with amino ligands (NH2). After this process, we did the folic acid funcionalization (FA-NH2). The FA ligands of the UCNPs can bind to the FA receptors of the cancer cells, such as cervical and breast cancer.