Photosensitizer Ce6 and anti-EpCAM, a highly expressed monoclonal antibody in cancer stem cells of hepatocellular carcinoma, were linked to UCNP surfaces via the formation of amide linkage between carboxyl from Ce6 or anti-EpCAM and abundant amino from PEI, leading to the formation of Ps-Ce6 and anti-EpCAM-UCNPs-Ce6 nanoparticles. The gene discussed is EPCAM; the disease is cancer.