Dually functioned core-shell NaYF4:Er3+/Yb3+@NaYF4:Tm3+/Yb3+ nanoparticles as nano-calorifiers and nano-thermometers for advanced photothermal therapy

Abstract

To realize photothermal therapy (PTT) of cancer/tumor both the photothermal conversion and temperature detection are required. Usually, the temperature detection in PTT needs complicated instruments, and the therapy process is out of temperature control in the present investigations. In this work, we attempt to develop a novel material for achieving both the photothermal conversion and temperature sensing and control at the same time. To this end, a core-shell structure with NaYF4:Er3+/Yb3+ core for temperature detection and NaYF4:Tm3+/Yb3+ shell for photothermal conversion was designed and prepared. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Furthermore, the temperature sensing properties for the NaYF4:Er3+/Yb3+ and core-shell NaYF4:Er3+/Yb3+@NaYF4:Tm3+/Yb3+ nanoparticles were studied. It was found that the temperature sensing performance of the core-shell nanoparticles did not become worse due to coating of NaYF4:Tm3+/Yb3+ shell. The photothermal conversion behaviors were examined in cyclohexane solution based on the temperature response, the NaYF4:Er3+/Yb3+@NaYF4:Tm3+/Yb3+ core-shell nanoparticles exhibited more effective photothermal conversion than that of NaYF4:Er3+/Yb3+ nanoparticles, and a net temperature increment of about 7 °C was achieved by using the core-shell nanoparticles.

Up-conversion luminescence, temperature sensing properties and laser-induced heating effect of Er3+/Yb3+ co-doped YNbO4 phosphors under 1550 nm excitation

“…Several characteristic emissions of Er 3+ can be found in the UC luminescence spectra. Among them, two strong green emissions centered at around 545 and 565 nm can be assigned to the 2 H 11/2 , 4 S 3/2  →  4 I 15/2 transitions, and the red emission ranging from 650 to 740 nm originates from 4 F 9/2  →  4 I 15/2 transition 28,29 . In addition, an extremely weak near infrared emission located at 820 nm corresponding to 4 I 9/2  →  4 I 15/2 transition can also be observed 30 .…”

Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies

“…NIR excitation based cancer therapy using UCNP that lies in the biological windows is advantageous than quantum dots and other fluorophores. The NIR activation of UCNPs could accomplish photothermal conversion and provide deep tissue penetration ability [ 3 , 26 ]. The rare-earth doped NaYF 4 is attractive in biomedical applications as it gives high upconversion quantum yield than the quantum dots by two-photon energy transfer process from the sensitizer ion and the activator ion.…”

Graphene Quantum Dots-Driven Multiform Morphologies of β-NaYF4:Gd3+/Tb3+ Phosphors: The Underlying Mechanism and Their Optical Properties

“…Rare earth ion-doped phosphors possess potential applications such as solid-state lasers; 1 high-resolution display devices, security and brand protection, photodynamic therapy; 2 fluorescent labels for the detection of molecules; 3 in vivo imaging; 4,5 medical diagnostics, fingerprint detection, and sensors; 6,7 light-emitting devices; 8 solar cells; 9,10 and so forth which are better substitutes of conventional fluorophores and organic dyes. 11 Although the molar absorption coefficient of organic dyes and quantum dots is comparatively higher than that of the rare earth phosphors, high background noise, high blinking probability, poor photostability, and potential long-term toxicity hamper the use of these materials.…”