Y0.4Gd1.6O2S: Eu nanocrystals for ratiometric Pb2+ ions sensing via selectively non-radiative relaxation.

Toxic divalent lead ions are broadly chosen for famous perovskite systems with great optoelectronic performances, which motivates us to explore a novel strategy for its determination with high sensitivity. In this work, lanthanide doped inorganic oxysulfide nanocrystals (NCs) are verified to be excellent candidates for ratiometric Pb2+ ions sensing. Specifically, the photoluminescence (PL) intensity of Eu3+ ions in Y 0.4 Gd 1.6 O 2 S NCs decreases gradually with the increase of Pb2+ ions concentration under the excitation of 254 nm, while its intensity keep unchanged under 311 nm excitation. In this occasion, a ratiometric PL sensing route for Pb2+ ions is obtained through using I 311 as intrinsic reference. The detection limit for Pb2+ ions is 7.1 nM. This work provides a new ratiometric PL sensing route for Pb2+ ions via selectively non-radiative relaxation. • The PL intensity of Eu:Y 0.4 Gd 1.6 O 2 S NCs decreases with the addition of Pb2+ under 254 nm exicitation. • The PL intensity of Eu:Y 0.4 Gd 1.6 O 2 S NCs keep unchanged with the addition of Pb2+ under 311 nm exicitation. • A ratiometric PL sensing route for Pb2+ ions is obtained through using I 311 as intrinsic reference. • The detection limit for Pb2+ ions is 7.1 nM. [ABSTRACT FROM AUTHOR]