Smart YPO₄:Er–Yb Nanophosphor for Optical Heating, Hyperthermia, Security Ink, Cancer Endoradiotherapy, and Uranyl Recovery

Abstract

A YPO4:Er3+–Yb3+ nanophosphor has been synthesized by a facile coprecipitation method. The photon upconversion has been carried out at 980 nm continuous-wave laser diode excitation. Optical heating performance has been shown via the fluorescence intensity ratio (FIR) technique employed on two thermally coupled emitting levels: 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2. The calculated temperature gain (from ∼28 to 375 °C) under various pump powers is used in the hyperthermia-based medical treatment. The dispersion capability of the synthesized nanoparticles in the liquid reveals their usefulness in the development of security ink. For the first time, it is demonstrated that Er3+/Yb3+ ion codoped YPO4 could be used in the detection of uranyl ions up to a few ppm using the downconversion method. The beta (β) emission study shows its fruitfulness as a radioactive tracer as well as therapy for arthritis treatment. The nanomaterial was radiolabeled with β– emitting radionuclides 90Y [T 1/2 = 64.1 h; E β(max) = 2.28 MeV] and 177Lu [T 1/2 = 6.65 d; E β(max) = 497 keV; E γ = 208 keV (11.0%), 113 keV (6.4%)], and the radiolabeled formulation could be potentially used for delivery of an ionizing radiation dose to a malignant lesion site. Moreover, the hybrid (YPO4:Er3+–Yb3+@Fe3O4) formation with Fe3O4 has also been employed for potential applications in the therapy through hyperthermia heating as well as imaging. This study has shown the potential applications of phosphor in light conversion, optical heating, hyperthermia, security ink, uranyl ion detection, and radioactive labeling.

Fe3O4 Nanoparticles: Structures, Synthesis, Magnetic Properties, Surface Functionalization, and Emerging Applications

“…In addition to utilizing Fe 3 O 4 nanoparticles as the main core for further functionalization purposes, active MRI and hyperthermic Fe 3 O 4 NPs have been grafted onto the surface of Er 3+ /Yb 3+doped NaYF4@SiO2@AuNP core-shell nanoparticles to obtain near-infrared and magneticresponsive nanocomposites for hyperthermia treatment [132]. Combining an active optical heater Er 3+ /Yb 3+ -doped YPO 4 nanophosphor with magnetic hyperthermia Fe 3 O 4 agents into a hybrid material Er 3+ /Yb 3+ -doped YPO 4 @Fe 3 O 4 enhances the hyperthermic activity and ability to recover the material [133].…”

“…Combining an active optical heater Er 3+ /Yb 3+ -doped YPO4 nanophosphor with magnetic hyperthermia Fe3O4 agents into a hybrid material Er 3+ /Yb 3+ -doped YPO4@Fe3O4 enhances the hyperthermic activity and ability to recover the material [133].…”

Mesoporous NaGdF4/Ho–Yb@m-SiO2 Upconversion Nanophosphors as a Potent Theranostic Probe

“…Upconversion nanoparticles (UCNPs) have been used extensively in many applications because they have unique characteristics such as large anti-Stokes shift, good bio-compatibility, a high penetration depth of NIR (near infrared) light, tuning of emission intensity and wavelength through energy transfer or energy migration or energy accumulation, and metastable energy levels. − There are reports on use of UCNPs in biological applications for bio-imaging through MRI (magnetic resonance imaging), optical/fluorescence, CT (computerized tomography), and SPECT (single-photon emission CT). − One example is lanthanide (Ln 3+ )-doped carbon dots, which have been used in MRI/CT/FI (FI = fluorescence imaging) multimodal probes . However, it has limitations due to large ionic size differences between Ln 3+ and C dots, which make system unstable.…”

Enrichment of Crystal Field Modification via Incorporation of Alkali K+ Ions in YVO4:Ho3+/Yb3+ Nanophosphor and Its Hybrid with Superparamagnetic Iron Oxide Nanoparticles for Optical, Advanced Anticounterfeiting, Uranyl Detection, and Hyperthermia Applications

“…However, UV light is hazardous for the surrounding environment including the persons who are working. The number of literature studies using NIR light excitation is very less because of many limitations such as a very small spot size of the laser (1–2 mm diameter) and need of a proper collimator and proper filters. − However, if the above limitations are overcome, it has many advantages over UV light excitation because of deep penetration of the NIR light and thus materials having a few cm thickness can be detected.…”