3,5-Dihydroxy Benzoic Acid-Capped CaF₂:Tb³⁺ Nanocrystals as Luminescent Probes for the WO₄^2– Ion in Aqueous Solution

Abstract

We report a facile and effective luminescence method for the determination of the WO4 2– ion in aqueous medium at initial pH = 6.3. This is achieved using 3,5-dihydroxybenzoic acid-capped CaF2:Tb3+ (5%) nanocrystals (NCs) as a luminescent probe. This is accomplished based on the energy transfer luminescence from the WO4 2– ion to the Tb3+ ion in small-size CaF2:Tb3+ NCs. Hydroxyl groups on the surface ligand helps in binding the tungstate ion to the surface of the NCs. With the gradual addition of the WO4 2– ion, the intensity of the Tb3+ excitation and emission spectra significantly increased. The linear range of the detection was from 1 to 10 μM for the WO4 2– ion (R 2 = 0.99). The calculated detection limit was 0.4 μM (by applying the 3σ/K criterion).

Ultrasound-Assisted Synthesis of Luminescent Micro- and Nanocrystalline Eu-Based MOFs as Luminescent Probes for Heavy Metal Ions

“…Rare-earth-based metal-organic frameworks (MOFs) are actively used in various fields of science and technology as luminescent sensors [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ], LED components [ 12 ], luminescent probes for bioimaging [ 13 , 14 ], and luminescent thermometers [ 15 , 16 ]. Small-sized crystals of the rare-earth-based MOFs are especially interesting due to their unique properties.…”

CO32− ion-induced Cu2+ ion determination using DPA capped-LaF3:Eu3+ nanocrystals

“…ions in the FRET process between the analyte and the Tb 3+ ion. 38 We also developed a luminescence quenching method to determine KMnO 4 at the nanomolar scale in water using adenosine-CaF 2 :Eu 3+ NCs as the probe. 39 In the present work, we demonstrated the determination of Cu 2+ ions using DPA-capped LaF 3 :Eu 3+ (5%) nanocrystals (NCs) (shortly represented as nanoprobe) in water.…”

“…Here, the Tb 3+ ion luminescence intensifies with enhancement in the concentration of WO 4 2− ions in the FRET process between the analyte and the Tb 3+ ion. 38 We also developed a luminescence quenching method to determine KMnO 4 at the nanomolar scale in water using adenosine-CaF 2 :Eu 3+ NCs as the probe. 39…”

A Novel Solid Platform–Based Ag Nanoparticles Chemically Impregnated Activated Carbon for Selective Separation of Tungstate Species in Water: Kinetics and Thermodynamic Study

“…Thus, in batch experiments, the impact of the aqueous solutions pH (pH 2.0-10.0) on the tungstate (20.0 mg L −1 ) uptake by AgNPs/AC (0.05 ± 0.001 g) was studied after shaking for 1 h at 25 ± 1°C. Adusumalli et al 2020;Li et al 2019). .…”