Bismuth ion is an excellent activator and sensitizer for luminescent materials, which has been extensively studied during the recent decades. Bi3+‐doped phosphors have received considerable attention for their abundant emission colors covering the whole visible light region under ultraviolet (UV) and near ultraviolet (n‐UV) excitation, in flexible crystal structures. These phosphor materials have demonstrated potential applications in solid‐state lighting, display, biomedical, and optical sensing. Herein, the recent advances in the structure design and photoluminescence properties of Bi3+‐doped phosphors together with their white light emitting diode (WLED) applications are reviewed. The design strategies for crystal structure and the discovery of typical phosphors are systematically summarized, and the luminescent properties of Bi3+ can be effectively regulated by these strategies. Then, the design of polychromatic Bi3+‐doped phosphors produced by different doping ions is described, which in turn can adjust the emission colors and realize a single‐component white‐light emission. This review will promote researches on the discovery of new Bi3+‐doped phosphor materials, and the design strategies could provide an extensive guidance for the discovery and preparation of high‐efficient phosphors with color‐tunable emission including white‐emission for WLEDs in the future. Additionally, research progress of Bi3+‐doped perovskite and Bi2+‐doped phosphor materials is briefly elucidated.

Over the past two decades numerous studies have been reported on seaweeds-derived polysaccharides for biomedical and biological applications (tissue engineering, drug delivery, wound healing, and biosensor). Alginate, carrageenan, fucoidan, and ulvan are widely used marine derived polysaccharides for biological and biomedical applications due to their biocompatibility and availability. The gel forming property of alginate has increased its applications in tissue engineering and drug delivery as an extracellular matrix and delivery vehicle, respectively. Other sulfated polysaccharides such as carrageenan and fucoidan show promising application in tissue engineering due to their capacity of inducing important osteogenic, adipogenic, and chondrogenic differentiation in stem cells. In this review, we explained the extraction/isolation methods and applications of these seaweed derived polysaccharides as well as their roles in therapeutics, drug delivery, and tissue engineering.

Upconversion nanoparticles (UCNPs) and MnO 2 hybrid theranostic nanoplatform (UCMn) is highly desired; however, the rational design of such UCMn hybrid nanomaterials is still a great challenge. Herein, a simple and versatile strategy for the in situ growth of MnO 2 on the surfaces of UCNPs was reported using a sacrificial template method to construct an ideal MnO 2 -disguised and tumor microenvironment−triggered architecture. Such sophisticated architecture not only achieves activatable magnetic resonance imaging and restorable upconversion luminescence (UCL) imaging with over 100-fold enhancement of UCL in vivo but also significantly improves the efficiency of chemodynamic therapy (CDT) by glutathione depletion-and cisplatinactivation-enhanced • OH generation simultaneously. Additionally, the synergetic effect of CDT and chemotherapy presents excellent therapeutic effect in vivo as compared to either CDT or chemotherapy alone. We believe that the ideal design of the MnO 2 -disguised upconversion hybrid nanocomposite will provide more revelations on the future research on nanoscale theranostic systems.

Tumor therapy is facing great challenges in improving drug efficiency while reducing side effects. Herein, a novel multifunctional nanodrug carrier UC@mSiO 2 -RB@ZIF-O 2 -DOX-PEGFA (URODF) that combines oxygen (O 2 )enhanced photodynamic therapy (PDT) with pH-responsive chemotherapy is presented. Eight hundred eight nanometer NIR light-irradiated NaYF 4 :Yb/Er@NaYbF 4 :Nd@NaGdF 4 nanoparticles (UC) were employed as both upconversion/ magnetic resonance imaging matrix and motivator for photosensitizer in PDT with deep penetration depth. Mesoporous silica shell (mSiO 2 ) was used as the carrier for photosensitizer Rose Bengal (RB). Zeolitic imidazolate framework-90 (ZIF-90) was coated outside of mSiO 2 as O 2 reservoir to quickly release O 2 in tumor microenvironment and alleviate tumor hypoxia for enhanced PDT. Doxorubicin (DOX) and NH 2 -poly(ethylene glycol) modified folic acid (PEGFA) were covalently conjugated on the surface of nanoparticles for synergetic therapy. The drug-loading capacity reaches 5.6 and 6.0% for RB and DOX, respectively. In vitro and in vivo experiments demonstrate great therapeutic effect of URODF. This work presents for the first time a multifunctional nanodrug carrier that combines upconversion nanoparticles with metal−organic framework structure for O 2 -loaded combination therapy, which might open a promising way of enhancing tumor therapeutic efficacy.

Lead halide perovskite quantum dots (PQDs) have been widely recognized as highly luminescent materials for efficient optoelectronic applications owing to their fascinating electronic and optical properties. In spite of the excellent performances for the fabrication of lighting devices, the poor chemical instability greatly hampers their practical applications. The inevitable ion exchange and degradation driven from light, moisture, heat, and others limits their applications such as solid‐state light‐emitting diodes (LEDs). In this paper, the stability of PQDs is improved by integrating them in CaF2 hierarchical nanospheres (HNSs). In comparison with the pristine perovskite materials, the outstanding optical performances are well preserved. The perovskite displays a unique quantum confinement effect in the HNSs. Additionally, embedding the quantum dots in robust CaF2 matrices protects them from being damaged by moisture or light irradiation as well as anion exchange. Furthermore, white LED devices are obtained by mixing green CaF2‐CsPbBr3 composites and commercial red phosphors on a blue chip. The optimized devices show a high luminous efficacy of 62.7 lm W–1 under 20 mA current and preserve the value of 56.3 lm W–1 after working for 8 h.

efficiency,low-energy consumption, long lifetime, and environmental compatibility, and so on. [1][2][3] The common w-LEDs devices are fabricated via two combination strategies: 1) blue LED chip and yellow phosphor; 2) nearultraviolet (n-UV) LED chip and tricolor phosphors. [4,5] No matter for which fabrication methods, the development of red phosphor is crucial to improve the lighting quality and tune corrected color temperature of w-LEDs. [6,7] To date, many researchers have focused on exploring highly efficient red phosphors. Although Eu 2+ -doped nitride phosphors such as CaAlSiN 3 :Eu 2+ and Sr 2 Si 5 N 8 :Eu 2+[8-10] show high quantum yield (QY > 90%) and high thermal quenching temperature (>600 K), the harsh preparation conditions (high pressure ≥ 0.9-2.5 MPa; high temperature ≥1700-200 °C) and deepred emission position (beyond 650 nm) limit the large-scale application in indoor lighting. Eu 3+ -doped inorganic compounds are typical red-emitting phosphors due to the (4f 6 ) 5 D 0 → (4f 6 ) 7 F J spin-and parity-forbidden transition, [11,12] but it is hardly utilized in w-LEDs applications owing to the linearly narrow excitation and emission. [13,14] Mn 4+ has been considered as the promising red-emitting activator Nowadays, red phosphor plays a key role in improving the lighting quality and color rendering index of phosphor-converted white light emitting diodes (w-LEDs). However, the development of thermally stable and highly efficient red phosphor is still a pivotal challenge. Herein, a new strategy to design antithermal-quenching red emission in Eu 3+ , Mn 4+ -codoped phosphors is proposed.

Photoimmunotherapy can not only effectively ablate the primary tumor but also trigger strong antitumor immune responses against metastatic tumors by inducing immunogenic cell death. Herein, Cu2MoS4 (CMS)/Au heterostructures are constructed by depositing plasmonic Au nanoparticles onto CMS nanosheets, which exhibit enhanced absorption in near‐infrared (NIR) region due to the newly formed mid‐gap state across the Fermi level based on the hybridization between Au 5d orbitals and S 3p orbitals, thus resulting in more excellent photothermal therapy and photodynamic therapy (PDT) effect than single CMS upon NIR laser irradiation. The CMS and CMS/Au can also serve as catalase to effectively relieve tumor hypoxia, which can enhance the therapeutic effect of O2‐dependent PDT. Notably, the NIR laser‐irradiated CMS/Au can elicit strong immune responses via promoting dendritic cells maturation, cytokine secretion, and activating antitumor effector T‐cell responses for both primary and metastatic tumors eradication. Moreover, CMS/Au exhibits outstanding photoacoustic and computed tomography imaging performance owing to its excellent photothermal conversion and X‐ray attenuation ability. Overall, the work provides an imaging‐guided and phototherapy‐induced immunotherapy based on constructing CMS/Au heterostructures for effectively tumor ablation and cancer metastasis inhibition.

With multiphoton excited upconversion nanoparticles (UCNPs) as energy transducer, ultraviolet (UV) light responsive titanium dioxide (TiO 2 ) can be triggered indirectly by near-infrared (NIR) light for deep-tissue photodynamic therapy (PDT) through the fluorescence resonance energy transfer (FRET) strategy. Compared to pristine TiO 2 , absorption of hydrogenated black TiO 2 (H-TiO 2 ) in visible (vis) and NIR regions presents a marked improvement in performance, which leads H-TiO 2 to enhance its overall activity. Owing to the light absorption enhancement, the single component H-TiO 2 can be served as vis-driven photosensitizers (PSs) for PDT as well as NIR-triggered photothermal agents (PTAs) for photothermal therapy (PTT) simultaneously. Herein, H-TiO 2 decorated Nd 3+ -sensitized-UCNPs (Nd:UCNPs@H-TiO 2 ) nanocomposites (NCs) were synthesized by Nd:Y 3 Al 5 O 12 (Nd:YAG) pulsed-laser irradiation of Nd:UCNPs@TiO 2 precursors in suspended aqueous solution. Pulsed-laser modified synthesis is the optimum selection for preparing H-TiO 2 to meet the requirement for dispersion of biomaterials. Nd:UCNPs can convert 808 nm light energy to upconverting green emission for activating the attached H-TiO 2 to produce reactive oxygen species (ROS). Meanwhile, H-TiO 2 can directly convert 808 nm light energy to hyperthermia together with infrared photothermal and photoacoustic signals. The Nd:UCNPs@H-TiO 2 NCs exhibit remarkable photoconversion effects as NIRresponsive theranostic agents for accurate diagnosis and efficient phototherapy of tumors.