Thermally enhanced photoluminescence and temperature sensing properties of Sc2_2W3_3O12_{12}:Eu3+^{3+} phosphors

Currently,lanthanide ions doped luminescence materials applying as optical thermometers have arose much concern. Basing on the different responses of two emissions to temperature, the fluorescence intensity ratio (FIR) technique can be executed and further estimate the sensitivities to assess the optical thermometry performances. In this study, we introduce different doping concentrations of Eu$^{3+}$ ions into negative expansion material Sc$_2$W$_3$O$_{12}$:Eu$^{3+}$, accessing to the thermal enhanced luminescence from 373 to 548 K, and investigate the temperature sensing properties in detail. All samples exhibit good thermally enhanced luminescence behavior. The emission intensity of Sc$_2$W$_3$O$_{12}$: 6 mol% Eu$^{3+}$ phosphors reaches at 147.81% of initial intensity at 473 K. As the Eu doping concentration increases, the resistance of the samples to thermal quenching decreases. The FIR technique based on the transitions 5D0-7F1 (592 nm) and 5D0-7F2 (613 nm) of Eu$^{3+}$ ions demonstrate a maximum relative temperature sensitivity of 3.063% K-1 at 298 K for Sc$_2$W$_3$O$_{12}$:Eu$^{3+}$: 6 mol% Eu$^{3+}$ phosphors. The sensitivity of sample decreases with the increase of Eu$^{3+}$ concentration. Benefiting from the thermal enhanced luminescence performance and good temperature sensing properties, the Sc$_2$W$_3$O$_{12}$:Eu$^{3+}$: Eu$^{3+}$ phosphors can be applies as optical thermometers

Reinforced Self-Assembly of Donor–Acceptor π‑Conjugated Molecules to DNA Templates by Dipole–Dipole Interactions Together with Complementary Hydrogen Bonding Interactions for Biomimetics

One of the most important criteria for the successful DNA-templated polymerization to generate fully synthetic biomimetic polymers is to design the complementary structural monomers, which assemble to the templates strongly and precisely before carrying polymerization. In this study, water-soluble, laterally thymine-substituted donor–acceptor π-conjugated molecules were designed and synthesized to self-assemble with complementary oligoadenines templates, dA₂₀ and dA₄₀, into stable and tubular assemblies through noncovalent interactions including π–π stacking, dipole–dipole interactions, and the complementary adenine-thymine (A-T) hydrogen-bonding. UV–vis, fluorescence, circular dichroism (CD), atomic force microscopy (AFM), and transmission electron microscopy (TEM) techniques were used to investigate the formation of highly robust nanofibrous structures. Our results have demonstrated for the first time that the dipole–dipole interactions are stronger and useful to reinforce the assembly of donor–acceptor π-conjugated molecules to DNA templates and the formation of the stable and robust supramolecular nanofibrous complexes together with the complementary hydrogen bonding interactions. This provides an initial step toward DNA-templated polymerization to create fully synthetic DNA-mimetic polymers for biotechnological applications. This study also presents an opportunity to precisely position donor–acceptor type molecules in a controlled manner and tailor-make advanced materials for various biotechnological applications