An Ultra-stable Eu3+ Doped Yttrium Coordination Polymer with Dual-function Sensing for Cr(VI) and Fe(III) Ions in Aqueous Solution

The exploration of a dual-functional sensor is the key to effectively detect the Cr(VI) and Fe(III) cations in water, which is important to human health and environmental sustainability. Because of the phase stability and excellent luminescence, the rare-earth coordination polymers have great potential as dual-functional sensors. Here, we develop a Y 0.91 Eu 0.09 (H 2 O) 2 {C 6 H 3 (CO 2 ) 3 }(MIL-92(Y):9%Eu 3+ )-based dual-function luminescent sensor on Cr(VI) and Fe(III), which exhibits excellent phase stability and dispersibility in water. The luminescence of MIL-92(Y):9%Eu 3+ aqueous suspension quenches on Fe 3+ with Stern-Volmer constant K sv of 1.79 × 10 3 M -1 and limit of detection of 17 μM. The MIL-92(Y):9%Eu 3+ aqueous suspension also has turn-off sensing ability towards Cr 2 O 7 2- and CrO 4 2- with K sv values of 3.5 × 10 3 and 6.14 × 10 3 M -1 , respectively. It has detection limitations of 10 and 5 μM on Cr 2 O 7 2- and Cr 2 O 7 2- ions, respectively.