Novel room temperature ionic liquid for fluorescence enhancement of Eu3+ and Tb3+

►The use of an ionic liquid to enhance the fluorescence of lanthanides, Eu3+ and Tb3+ is discussed in this paper. ► This study represents the first report of the use of a tailored ionic liquid for the purposes of fluorescence enhancement. ► The fluorescence enhancement is achieved both a process of ligand sensitization, as well as reducing the non-radiative decay channels. ► The first point is achieved by the use of an anion capable of ligand sensitization, while reduction of non-radiative channels from the ionic liquid providing a non-aqueous environment. ► The ionic liquid prepared and used in this study is 1-butyl-3-methylimidazolium benzoate, ([bmim][BA]). ► The large fluorescence enhancement due to ligand sensitized fluorescence observed with [bmim][BA] diluted in [bmim][Tf2N], leads to nanomolar detection of the lanthanides.