The NIR light-induced imaging-guided cancer therapy is a promising route in the targeting cancer therapy field. However, up to now, the existing single-modality light-induced imaging effects are not enough to meet the higher diagnosis requirement. Thus, the multifunctional cancer therapy platform with multimode light-induced imaging effects is highly desirable. In this work, captopril stabilized-Au nanoclusters Au₂₅(Capt)₁₈−(Au₂₅) are assembled into the mesoporous silica shell coating outside of Nd³⁺-sensitized upconversion nanoparticles (UCNPs) for the first time. The newly formed Au₂₅ shell exhibits considerable photothermal effects, bringing about the photothermal imaging and photoacoustic imaging properties, which couple with the upconversion luminescence imaging. More importantly, the three light-induced imaging effects can be simultaneously achieved by exciting with a single NIR light (808 nm), which is also the triggering factor for the photothermal and photodynamic cancer therapy. Besides, the nanoparticles can also present the magnetic resonance and computer tomography imaging effects due to the Gd³⁺ and Yb³⁺ ions in the UCNPs. Furthermore, due to the photodynamic and the photothermal effects, the nanoparticles possess efficient in vivo tumor growth inhibition under the single irradiation of 808 nm light. The multifunctional cancer therapy platform with multimode imaging effects realizes a true sense of light-induced imaging-guided cancer therapy.

In this work, a simple method is demonstrated for the synthesis of multifunctional core–shell nanoparticles NaYF₄:Yb,Er@NaYF₄:Yb@NaNdF₄:Yb@NaYF₄:Yb@PAA (labeled as Er@Y@Nd@Y@PAA or UCNP@PAA), which contain a highly effective 808-nm-to-visible UCNP core and a thin shell of poly(acrylic acid) (PAA) to achieve upconversion bioimaging and pH-sensitive anticancer chemotherapy simultaneously. The core–shell Nd³⁺-sensitized UCNPs are optimized by varying the shell number, core size, and host lattices. The final optimized Er@Y@Nd@Y nanoparticle composition shows a significantly improved upconversion luminescence intensity, that is, 12.8 times higher than Er@Y@Nd nanoparticles. After coating the nanocomposites with a thin layer of PAA, the resulting UCNP@PAA nanocomposite perform well as a pH-responsive nanocarrier and show clear advantages over UCNP@mSiO₂, which are evidenced by in vitro/in vivo experiments. Histological analysis also reveals that no pathological changes or inflammatory responses occur in the heart, lungs, kidneys, liver, and spleen. In summary, this study presents a major step forward towards a new therapeutic and diagnostic treatment of tumors by using 808-nm excited UCNPs to replace the traditional 980-nm excitation.

A novel nanoplatform based on tungsten oxide (W₁₈O₄₉, WO) and indocyanine green (ICG) for dual-modal photothermal therapy (PTT) and photodynamic therapy (PDT) has been successfully constructed. In this design, the hierarchical unique nanorod-bundled W₁₈O₄₉ nanostructures play roles in being not only as an efficient photothermal agent for PTT but also as a potential nanovehicle for ICG molecules via electrostatic adsorption after modified with trimethylammonium groups on their surface. It is found that the ability of ICG to produce cytotoxic reactive oxygen species for PDT is well maintained after being attached on the WO, thus the as-obtained WO@ICG can achieve a synergistic effect of combined PTT and PDT under single 808 nm near-infrared (NIR) laser excitation. Notably, compared with PTT or PDT alone, the enhanced HeLa cells lethality of the 808 nm laser triggered dual-modal therapy is observed. The in vivo animal experiments have shown that WO@ICG has effective solid tumor ablation effect with 808 nm NIR light irradiation, revealing the potential of these nanocomposites as a NIR-mediated dual-modal therapeutic platform for cancer treatment.

ZnGa₂O₄ and ZnGa₂O₄: Mn²⁺/Eu³⁺ with uniform nanosphere (diameter about 400 nm) morphology have been synthesized via a facile hydrothermal approach. XRD, Raman spectra, XPS, FT-IR, SEM, TEM, photoluminescence (PL), and cathodoluminescecne (CL) spectra are used to characterize the resulting samples. The controlled experiments indicate the dosage of trisodium citrate and pH values are responsible for shape determination of the ZnGa₂O₄ products. The possible fast crystallization–dissolution–recrystallization formation mechanism for these nanospheres is presented. Under UV light and low-voltage electron beam excitation, ZnGa₂O₄, ZnGa₂O₄: Mn²⁺ and ZnGa₂O₄: Eu³⁺ emit bright blue, green, and red luminescence, respectively. Based on density functional theory calculations from first principles, the green and red emission are caused by the Mn 3d and Eu 4f electronic structures, respectively. Besides, the dependence of the CL intensity on the calcination temperature and electrical conductivity of the samples is presented. The ZnGa₂O₄: Mn²⁺ nanospheres have a higher CL intensity than that of bulk samples under the same excitation condition. The realization of three primary colors from a single host material suggests that full color display based on ZnGa₂O₄ nanospheres might be achievable, showing that these materials have potential applications in lighting and display fields.

Ce³⁺-, Tb³⁺-, and Dy³⁺-activated Y₄Si₂N₂O₇ phosphors have been prepared by the Pechini-type sol–gel method followed by ammonolysis of the precursors. The phase purity, morphology, crystallization condition, chemical composition, and thermal stability of the products have been studied carefully by X-ray diffraction (XRD), energy-dispersive X-ray (EDX), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), fourier-transform infrared (FTIR), and thermogravimetry analysis (TGA) techniques. The photoluminescence (PL) and cathodoluminescence (CL) properties of Ce³⁺-, Tb³⁺-, and Dy³⁺-doped Y₄Si₂N₂O₇ phosphors were also investigated. The electronic structure of Y₄Si₂N₂O₇ has been investigated by density-functional theory methods. The calculations revealed that the nitrogen atom contributes more excited electrons than the O atom. The band gap has been calculated through the reflection spectrum of the Y₄Si₂N₂O₇ host. For Ce³⁺/Tb³⁺/Dy³⁺ singly doped Y₄Si₂N₂O₇ products, the phosphors give the typical emissions of the activators. The energy transfers from Ce³⁺ to Tb³⁺ and Dy³⁺ ions have been found and demonstrated through the PL spectra and luminescence decay times. The emission color of Y₄Si₂N₂O₇:Ce³⁺, Tb³⁺ and Y₄Si₂N₂O₇:Ce³⁺, Dy³⁺ samples can be tuned by energy transfer processes. Additionally, the temperature-dependent PL properties and the degradation property of CL under continuous electron bombardment of the as-synthesized phosphors prove that the Y₄Si₂N₂O₇ host has good stability. Therefore, the Y₄Si₂N₂O₇:Ce³⁺, Tb³⁺, Dy³⁺ phosphors could serve as a promising candidate for UV W-LEDs and FEDs.

We present the fabrication, upconversion-luminescence cell imaging, and drug-storage/release properties of upconversion-luminescent core/mesoporous-silica-shell-structured β-NaYF₄:Yb³⁺,Er³⁺@SiO₂@mSiO₂ composite nanospheres with a size of 80 nm. The biocompatibility test on L929 fibroblast cells using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay reveals the low cytotoxicity of the system. The drug-storage and in vitro release tests indicate that these multifunctional nanomaterials have controlled drug-loading and -release properties for ibuprofen (IBU). Moreover, the upconversion (UC) emission intensity of IBU-β-NaYF₄:Yb³⁺,Er³⁺@SiO₂@mSiO₂ composite nanospheres increases gradually along with the released amount of IBU. Additionally, upconversion luminescence images of β-NaYF₄:Yb³⁺,Er³⁺@SiO₂@mSiO₂ uptaken by cells show clear green emission under 980 nm infrared laser excitation. These findings make these material promising for applications in the bioimaging, drug delivery, and disease therapy fields on the basis of its upconversion-luminescent and mesoporous properties.