Lanthanide complexes with organic ligands (including hydrocarbons) find application in medicien as luminescent biomarkers for various pathogenic bacteria. At the same time, starch (as a polysaccharide) can serve as a source for carbon nanoparticles (via thermal decomposition) that have very intensive and longliving luminescence, thus such nanoparticles conjunctioned with lanthanides may be used to create more effective medical probes.