The presently claimed and disclosed inventions relate, in general, to methods of radiation dosimetry and imaging using scintillation luminescence. More particularly, materials having a scintillation luminescence response to radiation that varies with total radiation dose received can be used for dosimetry monitoring, including, but not limited to nanoparticles for in vivo, real-time dosimetry. Energy-transfer nanocomposite materials as well as methods of making and using such materials in various applications including, but not limited to, in vivo radiation dosimetry and imaging, are disclosed. More particularly, the presently claimed and disclosed inventions relate to nanoparticle scintillation luminescence particles encapsulated in hosts of the general formula BaFX and BaFX:Eu.sup.2+ where X=Cl, Br and I.