Silica nanoparticles with Tb(III)-centered luminescence decorated by Ag 0 as efficient cellular contrast agent with anticancer effect.

The present work introduces composite luminescent nanoparticles (Ag0 -Tb3+ -SNs), where ultra-small nanosilver (4 ± 2 nm) is deposited onto amino-modified silica nanoparticles (35±6 nm) doped by green luminescent Tb(III) complexes. Ag0 -Tb3+ -SNs are able to image cancer (Hep-2) cells in confocal microscopy measurements due to efficient cell internalization, which is confirmed by TEM images of the Hep-2 cells exposed by Ag0 -Tb3+ -SNs. Comparative analysis of the cytotoxicity of normal fibroblasts (DK-4) and cancer cells (Hep-2) incubated with various concentrations of Ag0 -Tb3+ -SNs revealed the concentration range where the toxic effect on the cancer cells is significant, while it is insignificant towards the nonmalignant fibroblasts cells. The obtained results reveal Ag0 -Tb3+ -SNs as good cellular contrast agent able to induce the cancer cells death, which makes them promising theranostic in cancer diagnostics and therapy.