Ce 3+ Sensitized YPO 4 :Tb 3+ as Luminescent Probe for Selective Detection of Cu 2+ Ions

Poly (acrylic acid) (PAA) modified water dispersible Ce 3+ (5 at.%) sensitized YPO 4 doped with Tb 3+ (5 at.%) nanocrystals were prepared by polyol method. Structural characterization was thoroughly studied with X-ray diffraction (XRD). Transmission electron microscopy (TEM) image indicate the rod shape morphology of the synthesized material. Fourier transform infrared (FTIR) spectroscopy confirms the surface functionalization of these nanorods. The sample shows the occurrence of strong energy transfer from Ce 3+ ions to Tb 3+ ions. The emission from Tb 3+ ions (green colour) could be selectively quenched with the addition of Cu 2+ ions upto ~89% compared to many of the heavy metal ions. It is established from the investigation the sensing is through dynamic quenching via resonance type energy transfer. The limit of detection calculated using Stern-Volmer relation is found to be 19 μM (~ 1 ppm). This nanophosphor could be a potential luminescent probe for Cu 2+ ions sensing.