Recognition of H₂PO₄^- and Cu²⁺ in Water by Luminescent Terbium Silica Xerogel

Terbium silica hybrid material with imidazole ring that can be emissive in water has been designed and showed host-guest interactions with specific ions (cations and anions). In detail, we studied the sensing abilities of this material by addition of the anions H₂PO^-₄, HSO^-₄, F^-, Cl^-, Brand I ^- to water suspension of the derived powders. Only dihydrogen phosphate resulted in the quenching of the lanthanide luminescence (detection limit 10^-5 M). The same way was found in Cu²⁺ ions which also gave rise to luminescence quenching (detection limit 10^-5 M). More interestingly, luminescent sol-gel films were successfully prepared by the same materials and exhibited emission responses to H₂PO₄ - and Cu²⁺. For the sake of improving its mechanical property, the robust and flexible inorganic/PMMA hybrid material with sensing capability was also developed for future use. © Springer Science+Business Media, LLC 2011.