Synthesis of high-quality lanthanide oxybromides nanocrystals with single-source precursor for promising applications in cancer cells imaging

Nanocrystals of lanthanide oxybromides (LnOBrs) with low-phonon energy and high chemical stability are of particular interest for lighting and bioimaging applications. Here, for the first time, we report the synthesis of high-quality LnOBr (Ln = La, Eu, Gd, Tb) nanocrystals using the thermal decomposition of single-source precursors. Moreover, this robust and facile method can be used to synthesize optically active ultrathin EuOBr nanosheets and Eu³⁺-doped LaOBr nanocrystals with unique luminescence properties. Importantly, for the first time, the application of Eu³⁺-doped LaOBr nanocrystals in cancer cell imaging has been demonstrated.