At the present, a large number of worldwide leading laboratories are engaged in the development of various types of multifunctional nanoparticles that can be used as containers for the drug delivery, which has led to the emergence of many innovative strategies in the diagnosis and treatment of diseases and new approaches to personalized medicine. It has been proven that nanoparticles can effectively be used to detect, visualize, and treat various tumors. The nanocontainers based on porous silicon nanostructures (pSi NSs), proposed in present project, have a number of undeniable advantages over other inorganic nanostructures used for drug delivery. The main advantage is their proven high biocompatibility, but also their complete biodegradability, as was previously published by Dr. Sivakov’s group. Due to the simplicity of PSi NSs modification, it is possible to ensure specific delivery of various drugs (hydrophobic and hydrophilic drugs, proteins, peptides, DNA, etc.) into cells in the required time intervals. Due to the presence of photoluminescence properties in pSi NPs, they can also be used as contrast agents for bioimaging. During this project, involved scientists from Vilnius University will be focused on the synthesis and surface modification (hydrophobic, hydrophilic) of novel upconverting nanoparticles (UCNPs) with core-shell architecture, where the desirable optical properties of UCNPs will be achieved by various combinations of lanthanide ions within the core and shells of synthesized particles. However, the emission of UCNPs in red spectral is less intensive in compare to visible or UV regions (in case of particle doped with Tm3+ ions). Therefore, new approaches to increase emissions in the red region of the spectrum remain highly desirable. For that reason, it is interesting to find out if it possible to develop novel UCNPs-silicon (nano)composites, in which, the relative high energy emission (UV – 600 nm) of UCNPs excited via NIR laser, could be effectively adsorbed by silicon
nanostructures, resulting to the system emission in red spectral range enhancement. In recent literature is reported several approaches of combination UCNPs to functional materials, such as bulk silicon and titania, enhancing sensing or photocatalytic properties. To summarize, all discussed before allows us to state the possible energy transfer from UCNPs to SiNSs and enhancement of red emission. Based on our knowledge and reported literature, the enhancement of porous and biocompatible silicon nanostructures red emission by their integration with UCNPs has not yet studied. The proposed scientific idea in frame of the proposed bilateral project has a high novelty potential due to the lack or weak paper related to the functional nanoparticle’s interaction with upconverting nanostructures. From this point of view the project has a strong innovation and potential for the long-term fruitful scientific cooperation between involved groups and institutions.

This project is funded by the German Research Foundation (DFG)