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The dependence of antibacterial activities on different crystallography facets has been demonstrated by taking Cu 2 O crystals as an example. Owing to the different atomic arrangement of the exposed surfaces, Cu 2 O octahedral crystals bounded by {111} facets exhibited higher activity in killing E. coli than cubic ones bounded by {100} facets. Zeta potential measurement demonstrated that the electrostatic interaction between E. coli and octahedral crystals was more profitable in inactivating bacteria than that between E. coli and cubic ones. Moreover, the suspending medium, where the bactericidal process takes place, has been found to play a crucial role on the bactericidal efficiency. This work presents a way for the sterilization or killing of bacteria efficiently and selectively.

191wileyonlinelibrary.com H 2 S homeostasis, yet the lack of powerful monitoring methods that could offer both spatial and temporal precision has hampered the investigation of H 2 S functions. Therefore, the rapid, facile, and reliable detection and monitoring of H 2 S with high sensitivity and selectivity in biological systems would be highly desirable and benefi cial.Fluorescence technique, especially small molecule fl uorescent sensors, has been employed in the noninvasive detection of H 2 S owing to its sensitivity and adaptability. [ 9 ] Despite the increasing effort in the preparation and study of suitable fl uorescent H 2 S sensors, there are still several challenges are present, 1) thiol containing biomolecules can interfere with H 2 S concentration reading due to the non-specifi city suffered from current luminescence probes, 2) the signal-to-noise ratio can also be compromised by the autofl uorescence generated by proteins and peptides within samples, 3) majority of the fl uorescent sensors require substantial incubation period to fully fl uoresce under mild physiological conditions, and 4) due to the intrinsic chemical instability of fl uorophores at excited state, fl uorescent sensors suffer from serious photobleaching and decomposition. Therefore alternative monitoring approaches are actively being pursued combing with the small molecule fl uorescent sensors together.With the unique ability to convert long-wavelength low energy light to short-wavelength high energy light, lanthanide-doped upconversion nanoparticles (UCNPs) have been Development of a Highly Selective, Sensitive, and Fast Response Upconversion Luminescent Platform for Hydrogen Sulfi de DetectionJuanjuan Peng , Chai Lean Teoh , Xiao Zeng , Animesh Samanta , Lu Wang , Wang Xu , Dongdong Su , Lin Yuan , * Xiaogang Liu , and Young-Tae Chang * Hydrogen sulfi de (H 2 S) has been recognized as one of most important gaseous signaling molecules mediated by a variety of physiological and pathological processes. Yet, its functions remain largely elusive due to the lack of potent monitoring methods. Hereby this issue is addressed with a powerful new platform-dye-assembled upconversion nanoparticles (UCNPs). A series of chromophores with different absorption bands and fast responses towards H 2 S is combined with UCNPs and results in a library of H 2 S sensors with responsive emission signals ranging from the visible to the near-infrared (NIR) region. These nanoprobes demonstrate highly selective and rapid responses to H 2 S in vitro and in cells. Furthermore, H 2 S levels in blood can be detected using the developed nanoprobes. Hence the reported H 2 S sensing platform can serve as a powerful diagnostic tool to research H 2 S functions and to investigate H 2 S-related diseases.

Reducing the toxic Pb component in perovskites is an important step to realize environment-friendly perovskite optoelectronic devices. Herein, the structural, electronic, and optical properties of Zn and Mn codoped CsPbBr 3 have been investigated based on firstprinciple calculations and experimental verifications. Although the Zn dopant could reduce the optical band gap and exciton binding energy and enhance the optical absorption and defect tolerance for CsPbBr 3 , the maximum reduction of the toxic Pb component was just about 12.5% in the experiment because the Zn dopant enlarges the formation energy of CsPb 1−x Zn x Br 3 . For the stable CsPb 1−x−y Mn x Zn y Br 3 perovskite, the largest y and corresponding (x + y) could reach up to 25% and 83% respectively, since the Mn dopant could reduce the structural disorder. Especially when (x + y) < 50%, CsPb 1−x−y Mn x Zn y Br 3 exhibits a comparable carrier lifetime and exciton binding energy with a lower band gap to those of the CsPbBr 3 , since the Zn dopant supplies a charge to CsPbBr 3 to counteract the variation of Pb−Br bonds induced by the Mn dopant. Meanwhile, the d orbitals of the dopant increase the optical absorption. These suggest that a 50% reduction of toxic Pb could be realized for stable CsPb 1−x−y Mn x Zn y Br 3 with negligibly deteriorated optoelectronic properties. This work provides an alternative approach to achieve a Pb-less perovskite with a high performance.

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Nanoparticle emitting short-wave infrared (SWIR) light has received increased attention in the molecular imaging field due to its deeper tissue penetration, fast imaging, high sensitivity, and resolution. The simultaneously activated SWIR excited directly by an 808 nm laser and T 1 -weighted magnetic resonance imaging (MRI) signal are found in one single-shell nanoparticle NaErF 4 @NaGdF 4 (Er@Gd), which is used as a dual-modality imaging contrast agent in vivo to accurately determine the position of tumors. The conjugated cypate is then aggregated on the surface of Er@Gd@SiO 2 -Cy/bovine serum albumin. With the guidance of dual modality imaging, photothermal therapy is effectively used to ablate tumors in a mouse model. The design of single-shell nanomaterial activation of SWIR imaging and MRI signals is expected to provide a new strategy for high penetration and spatial resolution cancer theranostics.

light-emitting diodes (OLEDs), which can be mainly classified into several categories: metal complexes, [2] π-conjugated macromolecules, [3] and organic donor-acceptor (D-A) small molecules, [4] etc. Although the highly efficient NIR phosphorescent OLEDs have been reported, some addressed issues still remain a great challenge. For instance, the maximal external quantum efficiency (η EQE ) usually appears at very low current density, and the efficiency roll-off becomes serious at high current density, which can be ascribed to the intrinsic long lifetime of triplet excitons in NIR phosphorescent OLEDs. [5] As a comparison, the metal-free organic NIR fluorescent materials are an alternative competitor to solve these problems, as a result of the fluorescence nature with shorter (by three or more orders of magnitude) lifetime. Moreover, pure organic materials possess many other advantages such as rich chemical modification, easy synthesis, and low cost. To obtain the organic NIR emission, two kinds of molecular design strategies are generally employed to narrow the optical bandgap. One is to extend the π-conjugation of chromophores, but it is ultimately converged to a limited redshift for NIR emission, as well as the increased difficulty from synthesis, purification, and device fabrication. The other way is to construct NIR chromophores using D-A molecular architecture, which is a class of promising NIR materials for NIR OLED applications, due to very large tunable range of bandgap from CT-featured emissive state, along with ambipolar charge transport and easy device fabrication by vacuum evaporation.However, most of D-A molecular systems exhibit very low efficiency in photoluminescence (PL). As for the reasons, on one hand, due to the spatially separated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) in D-A system, CT emissive state usually leads to a low radiative rate or even no emission at all. On the other hand, the low efficiency can be ascribed to an intrinsic limitation of the energy gap law, [6] which results in the accelerated nonradiative process with the decrease of energy gap, as a result of the increased overlap of vibration wavefunction between ground state and excited state. In addition, the spin statistics is Herein, a high-efficiency near-infrared (NIR) material PXZ-3-NZP is designed and sythesized using the concept of hybridized local and charge-transfer (CT) state (HLCT), which is composed of donor (D) and acceptor (A) moieties as well as 10-substituted isomeride PXZ-10-NZP for the purpose of comparison and deep understanding on the essential difference of their excited state properties. As a result, the nondoped electroluminescent (EL) device of PXZ-3-NZP exhibits an excellent NIR emission (λ max = 738 nm) with a maximum external quantum efficiency (η EQE ) of 0.82% and a Commission International de L'clairage coordinate of (0.70, 0.29), which is record-setting among NIR fluorescent organic light emitting diodes with similar EL chromaticity. Also, a hi...

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