Two emissive cellulose hydrogels for detection of nitrite using terbium luminescence

Here two novel terbium silica xerogels (H-a and H-b) were assembled into cellulose hydrogels and two transparent films with narrow emission were successfully fabricated as fluorescent probes. We have found that the nitrite addition entailed efficient quenching effects of the photoluminescence intensity, contrasting the stable emissions upon exposure to other comparative ions (SO42-, CO32-, ClO3-, NO3-, AcO-, OH-, F-, Cl-, Br-, l(-), K+, Na+, Fe2+, Mn2+, Pd2+, Cd2+, Co2+, Cu2+ and Fe3+). The recognition process may be ascribed to the coordination interaction between terbium ions and NO2-. Linear functions for spectroscopic titrations were obtained in both hydrogel-based films and the new soft sensors exhibit a dynamic range for determination of nitrite from 1 x 10(-5) to 1 x 10(-4) M. (C) 2012 Elsevier B.V. All rights reserved.