Luminescent lanthanide-based nanocomposites (LnNCs) with intense and stable luminescence in aqueous media are in high demand for sensing and biological applications. Herein we report a new watersoluble LnNCs that prepared through a very simple and green procedure, with bright green luminescence dominated by D-5(4)-> F-7(5) transition (542 nm) of Tb3+, showing improved luminescence behavior compared with the complex Tb(Sal)(3).2H(2)O (Sal = salicylic acid) and good luminescence stability in aqueous solution even for considerable time (3 weeks) ascribed to the protective effect of the clay substrate to the Tb3+ complex. Moreover, the material exhibits rapid and highly selective sensing of tetrahydrofuran (THF) and can be applied for detecting low THF content (0.1-6.0 vol%) in aqueous solution. (C) 2017 Elsevier Ltd. All rights reserved.