Asparagine modified downconversion NaGdF4:Dy3+/Tb3+ nanophosphor for selective and sensitive detection of Cu(ii) ion

Pure NaGdF 4 , NaGdF 4 :Dy 3+ , and Dy 3+ /Tb 3+ co-doped NaGdF 4 nanoparticles with different concentrations of Tb 3+ (ranging from 3 to 20 mol%) were prepared via hydrothermal method.