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As the two typical basic binary solid solutions of the relaxor-PbTiO3 family, Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) has been widely investigated, whereas Pb(Ni1/3Nb2/3)O3-PbTiO3 (PNN-PT) has not. Here, 1.5 mol% Sm-doped (1 − x)Pb(Ni1/3Nb2/3)O3–xPbTiO3, (1 − x)PNN–xPT:0.015Sm with x = 0.33–0.39, ceramics have been prepared and the chemical composition-induced evolution of crystal structure, domain, and electrical properties investigated systematically. With increasing PT content, evolution of the rhombohedral–tetragonal structure was observed. A rhombohedral–tetragonal morphotropic phase boundary occurred around x = 0.36–0.37, which showed a peak piezoelectric property with piezoelectric constant d33 = 531 pC N−1 and planar electromechanical coupling factor kp = 0.37 at room temperature. At the same time, the x = 0.36 composition showed improved ferroelectric behavior with remanent polarization Pr = 13.4 μC cm−2 and coercive field Ec = 3.2 kV cm−1. Interestingly, different from its PMN-PT counterpart, there is no temperature-driven phase transition between room temperature and the Curie temperature for (1 − x)PNN–xPT:0.015Sm. These parameters indicated that the PNN-PT system is worthy of more attention and is a promising platform for further development of high-performance piezo/ferroelectric materials. [ABSTRACT FROM AUTHOR]

In this study, self-powered photodetectors (PDs) sensitive to ultraviolet (UV) and short-wavelength blue (SWB) light were developed using a ZnO/SrTiO3 heterojunction, created through the magnetron sputtering technique. The photoresponse of the ZnO/SrTiO3 PDs showed significant enhancement following an annealing process. Post-annealing, the response (R) value of the ZnO/SrTiO3 PDs was recorded at 0.7 mA W−1, indicating an increase of 3.5 times compared to the pre-annealed state. Additionally, the rejection ratio between 390 nm and 450 nm (R390 nm/R450 nm) improved markedly from 6.21 to 38.16, demonstrating enhanced UV-SWB spectral discrimination. The rise and decay times for the annealed devices were measured at 35 μs and 3.5 ms, respectively. The observed enhancements in the performance of ZnO/SrTiO3 PDs are primarily attributed to the improved crystal quality of ZnO and the optimized intrinsic defect structures within the ZnO films due to annealing. This led to a strengthened internal electric field, facilitating the efficient separation and movement of photogenerated charge carriers. The outcomes of this study offer significant insights for the design and production of self-powered UV-SWB photodetectors. [ABSTRACT FROM AUTHOR]

Various yellowish-green persistent phosphors of Y2.95−x−yLuxGdyAl5−zGazO12:0.05Ce3+ (x = 0–1, y = 0–1, z = 1–4) were successfully synthesized by the one-step high-temperature solid-state reaction method in air. The effects of simultaneous doping of Lu3+, Gd3+ and Ga3+ on the luminescence properties of the phosphors were investigated in detail for the first time. Herein, the microstructure, morphology, afterglow performance, luminescence properties, thermoluminescence, thermal quenching and flicker index of the efficient blue-light-activated Y2.95−x−yLuxGdyAl5−zGazO12:0.05Ce3+ phosphors were tested. The τ90 and τ80 values of Y1.45LuGd0.5Al2.5Ga2.5O12:0.05Ce3+ are 10.8 ms and 33.2 ms, respectively. These parameters are important in terms of effectiveness in reducing flicker in alternating current (AC) LEDs. Compared with the conventional Y3Al2Ga3O12:Ce3+ phosphor, the Y1.45LuGd0.5Al2.5Ga2.5O12:0.05Ce3+ phosphor has a better luminescence performance, stronger afterglow performance, and lower flicker index. The quantum yield of the Y1.45LuGd0.5Al2.5Ga2.5O12:0.05Ce3+ phosphor was 86.42% and the luminous efficiency of the LED devices prepared with it reached 92.12 lm W−1 when operated at 100 mA. Integrating sphere and spectroradiometer tests as well as CIE chromaticity diagrams indicate that the AC-WLEDs assembled by mixing the Y1.45LuGd0.5Al2.5Ga2.5O12:0.05Ce3+ phosphor and a commercial red phosphor in an appropriate ratio could obtain ideal white light with a high color-rendering index (87.9) and the flickering index was successfully reduced from 100% to 61.4%. [ABSTRACT FROM AUTHOR]

An effective method to eliminate grain boundary resistance of crystalline vanadoborate electrolyte was developed. This method involved the addition of glycerol to result in the formation of many hydrogen bonds between crystal grains, facilitating a rapid transfer of protons across grain boundaries. Using this method, the intrinsic conduction of vanadoborate electrolyte was fully reflected in its bulk materials, valuable for advancing our understanding of vanadoborate electrolytes and for promoting the application of these electrolytes. [ABSTRACT FROM AUTHOR]

Breaking through the traditional 1,7,3,5-aryl substituted aza-BODIPY structure, asymmetric aza-BODIPYs, tBu-azaBDPs , containing non-aryl group at 3-site were prepared for the first time. tBu-azaBDP exhibited a severely twisted configuration. tBu-azaBDPs had a near-infrared fluorescence emission and high molar extinction coefficients. Although the barrier-free rotation of the distal –tBu group in tBu-azaBDP resulted in low fluorescence quantum yield, the photothermal conversion efficiency was markedly enhanced. tBu-azaBDP nanoparticles with laser irradiation were revealed to induce cell apoptosis in photothermal therapy. We consider that development of aza-BODIPYs with the barrier-free rotation of the –tBu group at 3-site provides a strong platform for design of phototherapy agents for cancer treatment in photothermal therapy by apoptosis. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) has been explored and acts as a practical analytical detection approach. However, constructing highly sensitive SERS substrates usually involves expensive materials and tedious preparation processes, and SERS substrates often cannot be reused. Herein, direct hetero-integration of three-dimensional graphene (3D-graphene) with silicon-on-insulator (SOI) substrate can be utilized as a highly stable, ultra-sensitive, low cost and reusable SERS substrates through plasma-assisted chemical vapor deposition (PACVD). The novel nanocavity construction of the 3D-graphene combines with the optical cavity system of the SOI to improve the interaction between the incident light and 3D-graphene, which is a model for doubly-reinforced Raman scattering. These properties enhance electronic interactions between 3D-graphene, target molecules, and SOI substrates, thereon improving chemical/charge transfer effects in heterojunctions. The as-designed 3D-graphene/SOI heterojunction has detection limits of ∼10−10 M for rhodamine B (RB) and rhodamine 6G (R6G), and the detection limit for crystalline violet (CRV) is ∼10−8 M, which is better than the existing reported graphene-based SERS. Our study confirms the efficient carrier transfer mechanism in the 3D-graphene/SOI heterojunction and enhances the chemical/charge transfer mechanism of SERS by double-enhanced high-light absorption. In addition, erythrosine B (EB) and carmine, considered harmful pigment additives in fruit-flavored beverages, were selected as the detection targets with a detection limit of about 10−9 M and 10−8 M, suggesting that 3D-graphene/SOI heterojunction-based SERS can be applied in the food safety field. [ABSTRACT FROM AUTHOR]

Ceramic-based dielectric capacitors have attracted ever-increasing interest owing to their wide applications in high-power and pulsed-power electronic systems. Nevertheless, synchronously achieving ultrahigh recoverable energy storage density (Wrec) and high efficiency (η) in dielectric ceramics is still a great challenge. Herein, when lead-free Bi0.9La0.1FeO3–Ba0.7Sr0.3TiO3–K0.5Na0.5NbO3 ceramics with a high disorder degree at the atomic scale was systematically explored, it exhibited an ultrahigh Wrec of 13.9 J cm−3 and high η of 89.6% due to the synergistic contribution of high maximum polarization Pmax, small remanent polarization Pr and large breakdown strength Eb. The high Pmax is generated because of the genes of BiFeO3, while the small Pr originates from the significantly enhanced relaxor behavior. In particular, the large Eb stems from multiple intrinsic and extrinsic factors, such as the decreased average grain size at the submicron scale and promoted electrical microstructure. Moreover, the ceramics displayed exceptional reliability and giant power density. These results not only demonstrate the great potential of BiFeO3-based dielectric ceramics in energy storage applications but also pave a feasible way to develop novel lead-free dielectric capacitors with extraordinary energy storage properties. [ABSTRACT FROM AUTHOR]

Developing an efficient strategy for obtaining proton conductors with wide working temperature domains is of great significance for the wide application of proton conductors. To date, proton conductors that have high proton conductivity from subzero temperatures to high temperatures above 100 °C have been very rare. Herein, we prepared two composites, H3PO4@MIL-101-SO3H(Cr) (1) and H2SO4@MIL-101-NH2(Al) (2) by applying a dual-modification strategy to functionalize MOF MIL-101, that is, incorporating acidic guest molecules into the channels of MIL-101 while modifying the MIL-101 backbone with functional groups. Both composites have high proton conductivity over a broad temperature domain (−40 °C to above 150 °C) due to the complementary conduction or synthetic conduction of the backbone functional group and acidic guest molecules in different temperature ranges. The proton conductivities of 1 are 0.9 × 10−1 S cm−1 at 65 °C and 95% RH, 7.5 × 10−5 S cm−1 at −40 °C and 1.4 × 10−2 S cm−1 at 150 °C. Further, the proton conductivities of 2 are 5.8 × 10−2 S cm−1 at 65 °C and 95% RH, 7.1 × 10−4 S cm−1 at −40 °C and 2.5 × 10−4 S cm−1 at 170 °C. All the proton conductivities of the two composites in three temperature domains (low, moderate and high temperature) are at a high level among those of reported proton conductors. Moreover, their proton conductivities have good stability and durability in the broad temperature region from subzero temperatures to high temperatures above 100 °C. [ABSTRACT FROM AUTHOR]

Through one-pot mechanochemical synthesis, a series of guests [imidazole, (aminomethyl)phosphonic acid, urea and sulfamic acid] are rapidly encapsulated into the pores of MOF NENU-3 while the MOF is formed. The synthesis of a MOF loaded with functional guests that used to take several days and require a multistep procedure can now be completed in one step within several minutes. The proton conductivities of the obtained composites increased by 2–3 orders of magnitude compared with NENU-3. [ABSTRACT FROM AUTHOR]

Three novel cicada-like nickel(II) clusters, formulated as [Ni6(bdped)2(mba)6(Hdmpz)2(NO3)2(H2O)2]·4MeCN (SD/Ni6b), [Ni5(bdped)2(tca)6(Hdmpz)(MeOH)2(H2O)]·MeOH (SD/Ni5a) and [Ni4(Hbdped)2(ba)4(Hdmpz)2]·2NO3·2MeCN (SD/Ni4a), were obtained by tuning the auxiliary carboxylic acids, where H2bdped = 1,2-bis-(3,5-dimethylpyrazol-1-yl)-ethane-1,2-diol; Hmba = 2-methylbenzoic acid; Hdmpz = 3,5-dimethyl-1H-pyrazole; Htca = 3-thiophenecarboxylic acid; and Hba = benzoic acid. The structures of SD/Ni6b, SD/Ni5a and SD/Ni4a are built from a central Ni4O4 opened cube, appending two to zero NiNO5 octahedra. The solution behaviours of SD/Ni6b, SD/Ni5a and SD/Ni4a were studied in detail via an ESI-MS technique and their solution stabilities were confirmed. Magnetic analysis indicated the presence of Ising-type anisotropy: D = −13, −10, and −11 cm−1 for SD/Ni6b, SD/Ni5a, and SD/Ni4a, respectively; moreover, dominantly ferromagnetic interactions were found between magnetic centers: J1 = 6.5 cm−1, J2 = −0.44 cm−1 and J1 = 5.9 cm−1, J2 = 2.6 cm−1 for SD/Ni5a and SD/Ni4a, respectively. Besides, the photocurrent signals were observed and they reached the maximum very quickly for these three nickel(II) clusters and then their current intensities remained almost constant, which provide a possibility to be used for light-harvesting and photo-related catalysis. [ABSTRACT FROM AUTHOR]

Designing the homogeneous assembly of the bio–nano interface to fine-tune the interactions between the nanoprobes and biological systems is of prime importance to improve the antimicrobial efficiency of nanomedicines. In this work, highly luminescent silver nanoclusters with the homogeneous conjugation of an antimicrobial peptide (referred to as Dpep-Ag NCs) were achieved via the reduction–decomposition–reduction process as a single package. The as-designed Dpep-Ag NCs inherited the two distinctive features of bactericides from the Ag+ species and the antimicrobial peptide of Dpep, and exhibited enhanced bacterial killing efficiency compared with other control groups including BSA-capped Ag NCs and the original antimicrobial peptide bactenecin (Opep)-protected Ag nanoparticles (Opep-Ag NPs). The ultrasmall size feature of Dpep-Ag NCs combined with the positively charged bactericidal tail allow a better interface and interaction with the cell membrane owing to the selective targeting of lipopolysaccharides in the Gram-negative bacteria and electrostatic interaction, facilitating the membrane permeability. Dpep-Ag NCs restrained the E. coli growth visibly and outperformed commercial Ag NPs (30 nm) with reduced (ca. 100-fold) minimal inhibitory concentration. The analysis of infected wound sizes and tissues treated with Dpep-Ag NCs in a murine model reveal obvious differences in the healing effect compared with the other counterparts, demonstrating its antibacterial efficiency in practical application. [ABSTRACT FROM AUTHOR]

Sr(Ti0.3Fe0.7)O3−δ (STF) and the associated exsolution electrodes Sr0.95(Ti0.3Fe0.63Ru0.07)O3−δ (STFR), or Sr0.95(Ti0.3Fe0.63Ni0.07)O3−δ (STFN) are alternatives to Ni-based cermet fuel electrodes for solid oxide electrochemical cells (SOCs). They can provide improved tolerance to redox cycling and fuel impurities, and may allow direct operation with hydrocarbon fuels. However, such perovskite-oxide-based electrodes present processing challenges for co-sintering with thin electrolytes to make fuel electrode supported SOCs. Thus, they have been mostly limited to electrolyte-supported SOCs. Here, we report the first example of the application of perovskite oxide fuel electrodes in novel oxygen electrode supported SOCs (OESCs) with thin YSZ electrolytes, and demonstrate their excellent performance. The OESCs have La0.8Sr0.2MnO3−δ–Zr0.92Y0.16O2−δ (LSM–YSZ) oxygen electrode-supports that are enhanced via infiltration of SrTi0.3Fe0.6Co0.1O3−δ, while the fuel electrodes are either Ni-YSZ, STF, STFN, or STFR. Fuel cell power density as high as 1.12 W cm−2 is obtained at 0.7 V and 800 °C in humidified hydrogen and air with the STFR electrode, 60% higher than the same cell made with a Ni-YSZ electrode. Electrolysis current density as high as −1.72 A cm−2 is obtained at 1.3 V and 800 °C in 50% H2O to 50% H2 mode; the STFR cell yields a value 72% higher than the same cell made with a Ni-YSZ electrode, and competitive with the widely used conventional Ni-YSZ-supported cells. The high performance is due in part to the low resistance of the thin YSZ electrolyte, and also to the low fuel electrode polarization resistance, which decreases with fuel electrode in the order: Ni-YSZ > STF > STFN > STFR. The high performance of the latter two electrodes is due to exsolution of catalytic metal nanoparticles; the results are discussed in terms of the microstructure and properties of each electrode material, and surface oxygen exchange resistance values are obtained over a range of conditions for STF, STFN, and STFN. The STF fuel electrodes also provide good stability during redox cycling. [ABSTRACT FROM AUTHOR]

Constructing acid–base pairs is one of the efficient strategies for the design of proton conductors with high conductivity, due to the ultrafast proton-hopping with a low energy barrier between a proton donor (acid group) and an acceptor (base group). In this study, an acid–base adduct polyamine–P2Mo5 model system was established, including adducts [C6N4H22][H2P2Mo5O23]·H2O (P2Mo5-TETA), [C4N3H16]2[P2Mo5O23]·H2O (P2Mo5-DETA), and [C2N2H10]2[H2P2Mo5O23] (P2Mo5-EN), (TETA = triethylenetetramine, DETA = diethylenetriamine, EN = ethanediamine). Proton conductivity analyses showed that adduct P2Mo5-EN exhibited the highest proton conductivity 1.13 × 10−2 S cm−1 at 65 °C and 95% RH, which was one and three orders of magnitude greater than those of P2Mo5-DETA and P2Mo5-TETA under the same conditions. Ea values of all three adducts are lower than 0.4 eV, which indicates that their proton transfer is attributed to the Grotthuss mechanism. Combined with visual structure analysis, the proton transport pathways of three adducts are highlighted. Moreover, we use this model system to discuss in detail the effect of pKa, proton density and size of polyamine molecules on the proton conductivity of organic amine-POM adducts. [ABSTRACT FROM AUTHOR]

Energy storage materials and their applications have attracted attention among both academic and industrial communities. Over the past few decades, extensive efforts have been put on the development of lead-free high-performance dielectric capacitors. In this review, we comprehensively summarize the research progress of lead-free dielectric ceramics for energy storage, including ferroelectric ceramics, composite ceramics, and multilayer capacitors. The results indicate that dielectric capacitors with both high energy density and high efficiency are feasible using the materials providing high breakdown electric field and a slim hysteresis loop. This article also lists the factors affecting the fabrication cost of dielectric capacitors, such as sintering temperature, raw material costs, and types of internal electrodes, to promote the industrial application of ceramic energy storage capacitors. [ABSTRACT FROM AUTHOR]

Engineering catalytic materials into appropriate structures to get the structural benefits is vital for harvesting unprecedented catalytic efficiency in the oxygen reduction reaction (ORR). Herein, well-dispersed and highly active iron carbide nanoparticles (Fe3C NPs) were encapsulated in multichannel hollow nanofibers (MHNFs) to construct Fe3C@MHNF catalysts, which were synthesized via simple electrospinning and calcination steps. The well-defined inner channels with high conductivity and a porous structure enable the rapid electron transfer and mass transport for the ORR. And the resulting hybrid electrocatalyst with Fe3C NPs serving as active sites exhibits highly efficient activity with a half-wave potential of 0.90 V vs. the reversible hydrogen electrode (RHE), which surpasses that of the commercial platinum on carbon (Pt/C) catalyst (a half-wave potential of 0.84 V vs. RHE). The catalyst shows robust durability with negligible activity decay after 10 000 cycles. Density functional theory calculations confirm that the introduction of MHNFs significantly improves the electron transfer and exchange capability. The formed interfacial region not only induces linear correlation in both electronic structures and binding energies but also alleviates the barrier of site-to-site electron transfer between Fe3C NPs and MHNFs for the ORR process. [ABSTRACT FROM AUTHOR]

We report a robust room temperature ferroelectric (FE) state in (1 − x)Pb0.99Nb0.02[(Zr0.57Sn0.43)0.933Ti0.067]0.98O3–xZnO ((1 − x)PNZST–xZnO) composites, where PNZST shows a predominant antiferroelectric (AFE) nature due to ZnO-induced internal strain. Upon heating, a FE-AFE transition occurs and generates high pyroelectric performance. The composite with x = 0.1 shows a peak pyroelectric coefficient of p = 2450.7 × 10−4 C m−2 K−1 and figures of merit of current responsivity Fi = 926.9 × 10−10 m V−1, voltage responsivity Fv = 1334.3 × 10−2 m2 C−1, and detectivity Fd = 1194.8 × 10−5 Pa−1/2, which are about two orders of magnitude higher than those of most perovskite pyroelectric oxides. More interestingly, the FE-AFE transition temperature, i.e., the temperature corresponding to peak pyroelectric performance, is tunable in a wide temperature range from 30 °C to 65 °C. This work not only provides a promising material candidate for high performance pyroelectric devices, but also an alternative idea to develop ferroelectric and pyroelectric properties based on antiferroelectric materials. [ABSTRACT FROM AUTHOR]

Pyroelectric materials have a huge market in daily life applications and high pyroelectric performances near room temperature are highly desired. Here we report high pyroelectric performance with adjustable peak performance temperature of 29–46.2 °C in the (1 − x)Pb0.99Nb0.02[(Zr0.57Sn0.43)0.937Ti0.063]0.98O3–xZnO ((1 − x)PNZST–xZnO) composite. The x = 0.1 composite has a peak pyroelectric coefficient of 1053.9 × 10−4 C m−2 K−1 and figures of merit of Fv = 1249.4 × 10−2 m2 C−1, Fd = 876.3 × 10−5 Pa−1/2, and Fi = 832.7 × 10−10 m V−1 at around 39 °C. It is found that a robust room temperature ferroelectric state is realized in antiferroelectric PNZST due to ZnO-induced internal strain. The thermal-driven ferroelectric to antiferroelectric transition leads to high pyroelectric performance. This work provides a promising material candidate for high performance pyroelectric devices. [ABSTRACT FROM AUTHOR]

To help those suffering from viral infections and cancers, scientists are exploring enhanced therapeutic methods via metal nanoclusters (MNCs). This is attributed to the size of the MNCs, which is close to the Fermi wavelength of electrons. The motion of the electrons on the three-dimensional scale is limited, and the continuous energy level structure becomes a distinctive split energy level structure. To help their targeting abilities, MNCs have been combined with biomolecules such as DNA, peptides, and proteins. This not only solves the problem of poor stability but also endows MNCs with new biological characteristics and with diverse structures. In this review, a broad overview of MNC design strategies and biomedical applications is provided. The urgent topics of viral infection and cancer therapies using biomolecules-MNCs are addressed. In addition, the binding modes and conformational changes in biomolecules and MNCs are specifically analyzed. [ABSTRACT FROM AUTHOR]

Recently developed Na1/2Bi1/2TiO3 (NBT)-based relaxor ferroelectric ceramics are promising lead-free candidates for dielectric energy storage applications because of their non-toxicity and outstanding energy storage properties. Their commercialization currently faces a challenge in that high recoverable energy-storage density (Wrec) and high energy-storage efficiency (η) cannot be achieved simultaneously. Different from the normal relaxor ferroelectrics whose energy storage density was improved by reducing the remanent polarization and increasing the electric breakdown strength, in this work, a lead-free antiferroelectric (AFE) was utilized to partially replace the NBT-based relaxor (RE) to change the shape of the polarization curve and increase the electric breakdown strength, while maintaining large maximum polarization. Based on this concept, a lead-free RE/AFE 0.94(Na0.82K0.18)1/2Bi1/2TiO3–0.06FeNbO4/0.96NaNbO3–0.04CaZrO3 (NKBT–FN/NN–CZ) composite ceramic is designed and investigated. Through heat treatment of powder and the traditional solid phase reaction method, NKBT–FN/NN–CZ relaxor/antiferroelectric composites with multi-phase structure of an antiferroelectric embedded in a relaxor ferroelectric were established, and narrow and oblique double hysteresis loops were achieved in these composites. A high Wrec of 2.85 J cm−3 and high η of 80% were simultaneously realized at the composition with a mass ratio of 70/30 at room temperature (RT). Furthermore, the newly developed composites exhibit better energy storage characteristics at 120 °C, with a high Wrec of 3.5 J cm−3 as well as a high η of 91%. This study demonstrates that the design of a relaxor/antiferroelectric composite provides a highly effective method to improve the energy storage performance of lead-free ceramics. [ABSTRACT FROM AUTHOR]

Point-of-care (POC) testing offers rapid diagnostic results. However, the quantification of current methods is performed using standard curves and external references, and not direct and absolute quantification. This paper describes an integrated multiplex digital recombinase polymerase amplification (ImdRPA) microfluidic chip which combines DNA extraction, multiplex digital RPA and fluorescence detection together in one chip, creating a "sample-in-multiplex-digital-answer-out" system. Multi-layer soft lithography technology was used, with polydimethylsiloxane (PDMS) as the chip material and a glass slide as the substrate. This microfluidic chip has a six-layer structure and screw microvalve control function. The sample preparation for the chip involved magnetic bead-based nucleic acid extraction, which was completed within 15 min without any instrument dependence. The dRPA region was divided into 4 regions (3 positive detection areas and 1 negative control area) and included a total of 12 800 chambers, with each chamber being able to contain a volume of 2.7 nL. The screw valve allowed for the reaction components of each specific goal to be pre-embedded in different regions of the chambers. The reagents were passively driven into the dRPA region using vacuum-based self-priming introduction. Furthermore, we successfully demonstrated that the chip can simultaneously detect three species of pathogenic bacteria within 45 min and give digital quantitative results without the need to establish a standard curve in contaminated milk. Moreover, the detection limit of this ImdRPA microfluidic chip was found to be 10 bacterial cells for each kind of pathogen. These characteristics enhance its applicability for rapid detection of foodborne bacteria at the point-of-care (POC). We envision that the further development of this integrated chip will lead to rapid, multiplex and accurate detection of foodborne bacteria in a feasible manner. [ABSTRACT FROM AUTHOR]

A pure-inorganic framework based on {P4MoV4MoVI2} clusters with rich phosphate groups has been synthesized. It underwent a single crystal to single crystal conversion in air to form a new framework with changes both in the metal valent state and coordination environment. The new framework exhibits an ultra-high proton conductivity of 1.33 × 10−2 S cm−1 at 95 °C and 98% relative humidity and excellent stability. [ABSTRACT FROM AUTHOR]

Sr(Ti1−xFex)O3−δ (STF) has recently been explored as an oxygen electrode for solid oxide electrochemical cells (SOCs). Model thin film electrode studies show oxygen surface exchange rates that generally improve with increasing Fe content when x < 0.5, and are comparable to the best Co-containing perovskite electrode materials. Recent results on porous electrodes with the specific composition Sr(Ti0.3Fe0.7)O3−δ show excellent electrode performance and stability, but other compositions have not been tested. Here we report results for porous electrodes with a range of compositions from x = 0.5 to 0.9. The polarization resistance decreases with increasing Fe content up to x = 0.7, but increases for further increases in x. This results from the interaction of two effects – the oxygen solid state diffusion coefficient increases with increasing x, but the electrode surface area and surface oxygen exchange rate decrease due to increased sinterability and Sr surface segregation for the Fe-rich compositions. Symmetric cells showed no degradation during 1000 h life tests at 700 °C even at a current density of 1.5 A cm−2, showing that all the STF electrode compositions worked stably in both fuel cell mode and electrolysis modes. The excellent stability may be explained by X-ray Photoelectron Spectroscopy (XPS) results showing that the amount of surface segregated Sr did not change during the long-term testing, and by relatively low polarization resistances that help avoid electrode delamination. [ABSTRACT FROM AUTHOR]

Rapid, efficient and accurate nucleic acid molecule detection is important in the screening of diseases and pathogens, yet remains a limiting factor at point of care (POC) treatment. Microfluidic systems are characterized by fast, integrated, miniaturized features which provide an effective platform for qualitative and quantitative detection of nucleic acid molecules. The nucleic acid detection process mainly includes sample preparation and target molecule amplification. Given the advancements in theoretical research and technological innovations to date, nucleic acid extraction and amplification integrated with microfluidic systems has advanced rapidly. The primary goal of this review is to outline current approaches used for nucleic acid detection in the context of microfluidic systems. The secondary goal is to identify new approaches that will help shape future trends at the intersection of nucleic acid detection and microfluidics, particularly with regard to increasing disease and pathogen detection for improved diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Solid oxide cells operated reversibly between fuel cell and electrolysis modes are promising for energy storage with extremely high capacity. La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) has become the dominant oxygen electrode material in electrolysis and reversible operation. However, LSCF has been widely reported to degrade due to Sr surface segregation. The present understanding is that the segregation rate and hence the degradation rate increases with increasing temperature and current density. Here we present a study of LSCF electrode performance and stability carried out with a series of extended life tests (1000 hours) over a range of temperatures and reversing current densities. Although the results at lower temperatures (650–700 °C) show the expected increase in segregation-induced degradation with increasing current density, at higher temperature (750 °C) stability is improved and the electrodes become fully stable at the highest current density of 1.5 A cm−2, maintaining a stable polarization resistance of 0.08 Ω cm2. This unexpected result is explained by the increased electrochemical activity of LSCF at the higher temperature and a very rapid development of a stable surface segregated Sr layer. [ABSTRACT FROM AUTHOR]

A diphosphine-protected 18-gold-atom nanocluster was isolated via a facile reduction of an AuI precursor by NaBH4. Its composition was identified as {[Au18(dppm)6Cl4]·C6H6·3Cl·PF6} (SD/Au18, SD = SunDi; dppm = bis-(diphenylphosphino)methane) by X-ray single crystal structural analysis. This nanocluster possesses a prolate shape and is built from an Au10 kernel (bi-octahedral Au6 units sharing one edge) fused with two Au7 caps via sharing six gold atoms. The identity of the Au18 cluster is further demonstrated by ESI-MS. The number of valence electrons of [Au18(dppm)6Cl4]4+ is 10 (n* = 18–4–4), which does not match with the known magic numbers according to the spherical jellium model, and elongated models must be considered. The special stability of the Au18 cluster likely arises from geometrical factors in the metallic core. Two charge states are reported for this system. This work not only presents the structure elucidation of a diphosphine-protected Au18 nanocluster, but also provides an important insight into the growth pattern of gold nanoclusters and the charge states they can achieve. [ABSTRACT FROM AUTHOR]

Compared to emissive silver-thiolate clusters, their alkynyl cousins are, however, usually luminescence silent. Herein we report a novel silver-alkynyl cluster based NbO-type framework (SD/Ag18) showing unprecedented triple emission spanning from the visible to near-infrared (NIR) region. It is a 3D framework constructed from a [Cl@Ag16] cluster based unit, which is further quadruply bridged by the surrounding four Ag atoms through Ag…Ag interactions, giving a 4-connected NbO topology. Although SD/Ag18 exhibits weak orange-red emission at room temperature, its emission becomes strong upon cooling, with three emission maxima at 524, 647 and 1036 nm, respectively, covering both the visible and NIR regions. The visible emissions involve triplet alkynyl-to-metal charge transfer mixed with a cluster-centered state, whereas the participation of cPrC≡C− in the frontier orbitals of the cluster may be responsible for the NIR emission. The unusual emissions, especially in the NIR-II region, are observed, for the first time, in silver complexes. [ABSTRACT FROM AUTHOR]

Chimeric antigen receptor T-Cell (CAR-T) immunotherapy has been regarded as one of the most promising methods for cancer therapy. How to verify CAR-T cell function and efficiency is very significant for clinical applications. Meanwhile, the identification of tumor cells/tissues is very important for tumor diagnosis and operation. In this study, biocompatible and mass-produced polydopamine (PDA) nanodots have been prepared by a facile method. Oxidized polydopamine (OPDA) can be synthesized by the reaction between PDA and hydrogen peroxide at atmospheric pressure and temperature, and it possesses both one-photon and two-photon fluorescence properties. OPDA nanodots can image living cells for long time periods without mitosis and proliferation inhibition. After ingestion of OPDA nanodots, Raji cells can be used to verify CAR-T cell lethality and efficiency by visualization through fluorescence. The fluorescence intensity change originating from the conversion of PDA into OPDA can function as a signal to identify the tumor and normal cells/tissues because of the different concentration of ROS in tumor cells (high) and normal cells (low). Therefore, the facile synthesis of mass-produced novel organic nanodots with two-photon fluorescence properties will have wide applications in long time living cell imaging without mitosis and proliferation inhibition, CAR-T cell function verification and tumor cell/tissue detection. [ABSTRACT FROM AUTHOR]

A pillar-layered microporous MOF (SD/Co3) has been constructed from trimeric {Co3(COO)6} clusters as SBUs and mixed ligands as linkers. It exhibits preferential selective adsorption of C2H2/C2H4, C2H2/C2H6 and CO2/N2, owing to its dual active sites including uncoordinated nitrogen sites from pyrimidine groups and unsaturated metal centres (UMCs) exposed in channels. [ABSTRACT FROM AUTHOR]