In situ formation and dispersion of lanthanide complexes in wormlike micelles.

Lanthanide-containing, water-based fluids normally suffer from low photoluminescent (PL) and/or colloidal stability, which greatly hinders their applications. Herein, we report the preparation of PL fluids which contain in situ formed europium complexes in aqueous solution. The strategy first relies on the construction of wormlike micelles by mixing a zwitterionic surfactant (tetradecyldimethylaminoxide, C14DMAO) and a tridentate ligand for a lanthanide cation (2,6-dipicolinic acid, DPA) in water. The addition of the dual-functionalized DPA to an aqueous solution of C14DMAO (100 mol L-1) induced non-monotonic rheological changes, with the expected formation of a pseudogemini surfactant at a DPA-to-C14DMAO molar ratio of approximately 1 : 2. When a third component of EuCl3 is introduced to this system, complexes formed in situ between Eu3+ and DPA, resulting in bright red-emission. Besides DPA, C14DMAO is also involved in the complexation, which squeezes out water molecules and greatly improves the PL stability of the fluid. The synergetic effect among Eu3+, DPA and C14DMAO leads to the high colloidal stability of the fluid, opening the door for a wide range of potential applications. Further tests indicate that this strategy can be easily expanded to other lanthanide cations such as Tb3+.

Metal-Organic Gels from Silver Nanoclusters with Aggregation-Induced Emission and Fluorescence-to-Phosphorescence Switching.

Luminescent metal nanoclusters (NCs) are emerging as a new class of functional materials that have rich physicochemical properties and wide potential applications. In recent years, it has been found that some metal NCs undergo aggregation-induced emission (AIE) and an interesting fluorescence-to-phosphorescence (F-P) switching in solutions. However, insights of both the AIE and the F-P switching remain largely unknown. Now, gelation of water soluble, atomically precise Ag9 NCs is achieved by the addition of antisolvent. Self-assembly of Ag9 NCs into entangled fibers was confirmed, during which AIE was observed together with an F-P switching occurring within a narrow time scale. Structural evaluation indicates the fibers are highly ordered. The self-assembly of Ag9 NCs and their photoluminescent property are thermally reversible, making the metal-organic gels good candidates for luminescent ratiometric thermometers.

Multi-Step and Switchable Energy Transfer in Photoluminescent Organosilicone Capsules.

Light-harvesting is of vital importance for many events, such as photosynthesis. To efficiently gather and transfer solar energy, delicate antenna is needed, which has been achieved by algae and plants. However, construction of efficient light-harvesting systems using multiple, artificial building blocks is still challenging. Here, blue-emitting organosilicone capsules containing carbon dots (denoted as CDs-Si) in ethanol are prepared, which can effectively transfer energy to green-emitting (silicone-functionalized bodipy, Si-BODIPY) or red-emitting (rhodamine b, RhB) dyes. In ternary system, sequential Förster resonance energy transfer from CDs-Si to Si-BODIPY and further to RhB is realized, which is accompanied with a less pronounced, parallel FRET directly from CDs-Si to RhB. The overall efficiency of energy transfer reaches ≈86%. By introducing a photoswitch (1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)-3,3,4,4,5,5-hexafluoro-1-cyclopentene, DAE) to the system, the emission becomes switchable under alternative illumination with UV and visible light, leading to the formation of smart artificial light-harvesting systems.

Combination of photosensitizer and immune checkpoint inhibitors for improving the efficacy of tumor immunotherapy.

As a new type of antitumor strategy, the combined application of photodynamic therapy and immunotherapy will be a breakthrough in the field of tumor therapy. In this study, PD-L1McAb&HMME@Clip is used as the carrier to improve the low tumor response rate of immune checkpoint inhibitors. Firstly, by passive targeting technology, the carrier is delivered to the tumor site to increase the local drug concentration. Then, by photodynamic technology, HMME can produce large amount of reactive oxygen species and directly kill the tumor cells. Meanwhile, the tumor cell lysate with strong immunogenicity can promote the phagocytosis of dendritic cells and the activation of initial T cells. Finally, by immune technology, the PD-1/PD-L1 pathway is blocked in the tumor microenvironment, the killing ability of T cells to tumor cells can be restored, and the tumor recurrence and metastasis can be effectively inhibited by the autoimmune system, so as to achieve the goal of tumor treatment. Furthermore, we also highlight the potential benefits of immunotherapy as a surgical adjuvant therapy.

Artificial Light-Harvesting System with White-Light Emission in a Bicontinuous Ionic Medium.

Artificial light-harvesting systems (ALHSs), which are closely related to Förster resonance energy transfer (FRET), are among the most attractive scientific topics during the past few decades. Specifically, binary ALHSs that are composed of a fluid donor and acceptor have a simplified composition and high number density of the donor units. However, largely due to the difficulty in obtaining a fluid donor, investigation of these systems is still quite limited, especially for the ionic systems. Herein, we report a new type of binary ALHS using an ionic naphthalimide (NPI) derivative as a donor, which shows greatly improved photoluminescence for its bicontinuous liquid structure. When blending with an acceptor such as rhodamine 6G or trans-4-[4-(dimethylamino)styryl]-methylpyridinium iodide, efficient FRET was confirmed by both experimental results and molecular dynamics simulations, with an energy transfer efficiency up to ∼90%. Tunable color, including white-light emission, was achieved by tuning the acceptor/donor ratio, opening the door for a variety of applications such as light-emitting diodes and photoluminescent inks.