The aim of the project is to obtain highly selective new generation fluorescence marker based on GQDs@MSNs nanocomposites via their functionalization with ligands specifically recognizing cancer cells, but also facilitating their transport through the cell membrane.

GQDs as unique carbon nanostructures are considered as a new class of fluorescence markers. Although the research devoted to their application in bioimaging is ongoing, their high selectivity towards cancer cells as well as investigations of their selective/targeted attachment and uptake by cancer cells still remain as a challenge. Therefore, the functionalization of such fluorescence markers with specific ligands is necessary. Such functionalization is foreseen to enable the targeted optical imaging via the improved and selective attachment, uptake and accumulation of fluorescence markers into cancer cells. For this purpose graphene quantum dots (GQDs) will be synthesized, and then biofunctionalized by ligands specifically recognizing cancer cells and facilitating their accumulation in tumors. These will be: (1) folic acid (FA), which can be actively recognized and bound to the folate receptor significantly overexpressed in human cancer cells, (2) LTVSPWY peptide as a targeting ligand toward HER2-positive breast cancer cells and (3) iRGD peptide, which is tumor-homing and tumor-penetrating peptide, that recognizes av integrins in cells.
Furthermore, the efficient functionalization, which simultaneously will not significantly affect the biocompatibility, monodispersity and fluorescence emission of these fluorescence markers, will open the next research stage concerning the efficiency of their selective attachment and uptake by cancer cell and determination of their nanotoxicity.