Erythritol as a Saccharide Multifunctional Electrolyte Additive for Highly Reversible Zinc Anode.

Dendrite formation and water-triggered side reactions on the surface of Zn metal anodes severely restrict the commercial viability of aqueous zinc-ion batteries (AZIBs). In this work, we introduce erythritol (Et) as an electrolyte additive to enhance the reversibility of zinc anodes, given its cost-effectiveness, mature technology, and extensive utilization in various domains such as food, medicine, and other industries. By combining multiscale theoretical simulation and experimental characterization, it was demonstrated that Et molecules can partially replace the coordination H2O molecules to reshape the Zn2+ solvation sheath and destroy the hydrogen bond network of the aqueous electrolyte. More importantly, Et molecules tend to adsorb on the zinc anode surface, simultaneously inhibit water-triggered side reactions by isolating water and promote uniform and dense deposition by accelerating the Zn2+ diffusion and regulating the nucleation size of the Zn grain. Thanks to this synergistic mechanism, the Zn anode can achieve a cycle life of more than 3900 h at 1 mA cm-2 and an average Coulombic efficiency of 99.77%. Coupling with δ-MnO2 cathodes, the full battery delivers a high specific capacity of 228.1 mAh g-1 with a capacity retention of 76% over 1000 cycles at 1 A g-1.

A three-dimensional "turn-on" sensor array for simultaneous discrimination of multiple heavy metal ions based on bovine serum albumin hybridized fluorescent gold nanoclusters.

Traditional single sensor is designed based on the "lock-and-key" mode, which only relies on the most dominant interactions between the sensing element and the target. Although it exhibits high selectivity, there are challenges in detecting multiple analytes at the same time. Here, a sensor array with three sensing elements is developed to detect multiple heavy metal ions simultaneously and quickly. In our experiment, bovine serum albumin-encapsulated gold nanoclusters (BSA-AuNCs) were used as fluorescence probes and three different dopamine (DA) concentrations as nonspecific receptors. As we know, self-polymerized polydopamine (PDA) can quench part of the fluorescence of BSA-AuNCs. Upon the addition of the heavy metal ions, the diverse non-specific interactions between DA and heavy metal ions result in the difference in the number of the remaining PDA. Therefore it would lead to different degrees of fluorescence recovery behavior. This unique "turn-on" fluorescence response mode can be analyzed by linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA). Two-dimensional, three-dimensional and even four-dimensional mixed ions detection and quantitative detection have also been achieved. Moreover, by using this fluorescence array mode, heavy metal ions in tap water or blood samples can be detected.

Defect-Rich Monolayer MoS2 as a Universally Enhanced Substrate for Surface-Enhanced Raman Scattering.

Monolayer 2H-MoS2 has been widely noticed as a typical transition metal dichalcogenides (TMDC) for surface-enhanced Raman scattering (SERS). However, monolayer MoS2 is limited to a narrow range of applications due to poor detection sensitivity caused by the combination of a lower density of states (DOS) near the Fermi energy level as well as a rich fluorescence background. Here, surfaced S and Mo atomic defects are fabricated on a monolayer MoS2 with a perfect lattice. Defects exhibit metallic properties. The presence of defects enhances the interaction between MoS2 and the detection molecule, and it increases the probability of photoinduced charge transfer (PICT), resulting in a significant improvement of Raman enhancement. Defect-containing monolayer MoS2 enables the fluorescence signal of many dyes to be effectively burst, making the SERS spectrum clearer and making the limits of detection (LODs) below 10-8 M. In conclusion, metallic defect-containing monolayer MoS2 becomes a promising and versatile substrate capable of detecting a wide range of dye molecules due to its abundant DOS and effective PICT resonance. In addition, the synergistic effect of surface defects and of the MoS2 main body presents a new perspective for plasma-free SERS based on the chemical mechanism (CM), which provides promising theoretical support for other TMDC studies.

Environment-friendly degradable zinc-ion battery based on guar gum-cellulose aerogel electrolyte.

With the vigorous development of electronics and the increasingly prominent problem of environmental pollution, it is particularly important to exploit environmentally friendly electronic devices. Transient electronics represent a kind of device that once the specified functions have completed can completely or partially disappear through physical or chemical actions. In this work, we introduce a novel guar gum-cellulose aerogel (GCA) membrane based on natural biomaterials and successfully use it as an electrolyte film to fabricate a degradable zinc-ion battery (DZIB). All components of the prepared DZIBs can be successfully degraded or disintegrate in phosphate-buffered saline (PBS) containing a solution of proteinase K after approximately 40 days. This electrolyte film has a high ionic conductivity of approximately 4.73 × 10-2 S cm-1 and a good mechanical stress property. When applied to DZIB, the production of zinc dendrites can be restrained, leading to the battery showing excellent electrochemical performance. The battery exhibits a specific capacity of 309.1 mA h g-1 at a current density of 308 mA g-1 after 100 cycles and a steady cycling ability (100% capacity retention after 200 cycles). More importantly, the electrochemical performance of DZIB is better than that of transient batteries reported in the past, taking a solid step in the field of transient electronics in the initial stage.

Surface Charge Transfer Doping of MoS2 Monolayer by Molecules with Aggregation-Induced Emission Effect.

Surface charge transfer doping has attracted much attention in modulating the optical and electrical behavior of 2D transition metal dichalcogenides (TMDCs), where finding controllable and efficient dopants is crucial. Here, 1,1,2,2-tetraphenylethylene (TPE) derivative molecules with aggregation-induced emission (AIE) effect were selected as adjustable dopants. By designing nitro and methoxyl functional groups and surface coating, controlled p/n-type doping can be achieved on a chemical vapor deposition (CVD) grown monolayer, MoS2. We investigated the electron transfer behavior between these two dopants and MoS2 with fluorescence, Raman, X-ray photoelectron spectra and transient absorption spectra. 1,1,2,2-Tetrakis(4-nitrophenyl)ethane (TPE-4NO2) with a negative charge aggregation can be a donor to transfer electrons to MoS2, while 1,1,2,2-Tetrakis(4-methoxyphenyl)ethane (TPE-4OCH3) is the opposite and electron-accepting. Density functional theory calculations further explain and confirm these experimental results. This work shows a new way to select suitable dopants for TMDCs, which is beneficial for a wide range of applications in optoelectronic devices.

A Novel 3D Hierarchical Plasmonic Functional Cu@Co3O4@Ag Array as Intelligent SERS Sensing Platform with Trace Droplet Rapid Detection Ability for Pesticide Residue Detection on Fruits and Vegetables.

Rapid and effective detection of pesticide residues from complex surfaces of fruits and vegetables has important significance. Herein, we report a novel three-dimensional (3D) hierarchical porous functional surface-enhanced Raman scattering (SERS) substrate, which is fabricated by successive two-step hydrothermal synthesis strategy of silver nanoparticles (Ag NPs) and cobalt oxide nanowires (Co3O4 NWs) on the 3D copper foam framework as Cu@Co3O4@Ag-H. The strategy offers a new avenue for localized plasmonic materials distribution and construction, which exhibits better morphology regulation ability and SERS activity (or hotspots engineering) than physical spurring obtained Cu@Co3O4@Ag-S. The developed Cu@Co3O4@Ag-H possesses large surface area and rich hotspots, which contributes to the excellent SERS performance, including homogeneity (RSD of 7.8%), sensitivity (enhancement factor, EF of 2.24 × 108) and stability. The Cu@Co3O4@Ag-H not only provides plenty of Electromagnetic enhancement (EM) hotspots but also the trace detection capability for droplet rapid sensing within 2 s. Cu@Co3O4@Ag-H substrate is further developed as an effective SERS sensing platform for pesticide residues detection on the surfaces of fruits and vegetables with excellent LOD of 0.1 ppm, which is lower than the most similar reported works. This work offers new potential for bioassay, disease POCT diagnosis, national security, wearable flexible devices, energy storage and other related fields.

ZIF-8/PI Nanofibrous Membranes With High-Temperature Resistance for Highly Efficient PM0.3 Air Filtration and Oil-Water Separation.

Air and water pollution poses a serious threat to public health and the ecological environment worldwide. Particulate matter (PM) is the major air pollutant, and its primary sources are processes that require high temperatures, such as fossil fuel combustion and vehicle exhaust. PM0.3 can penetrate and seriously harm the bronchi of the lungs, but it is difficult to remove PM0.3 due to its small size. Therefore, PM0.3 air filters that are highly efficient and resistant to high temperatures must be developed. Polyimide (PI) is an excellent polymer with a high temperature resistance and a good mechanical property. Air filters made from PI nanofibers have a high PM removal efficiency and a low air flow resistance. Herein, zeolitic imidazolate framework-8 (ZIF-8) was used to modify PI nanofibers to fabricate air filters with a high specific surface area and filtration efficiency. Compared with traditional PI membranes, the ZIF-8/PI multifunction nanofiber membranes achieved super-high filtration efficiency for ultrafine particles (PM0.3, 100%), and the pressure drop was only 63 Pa. The filtration mechanism of performance improvement caused by the introduction of ZIF-8/PI nanofiber membrane is explored. Moreover, the ZIF-8/PI nanofiber membranes exhibited excellent thermal stability (300 C) and efficient water-oil separation ability (99.85%).

Electrospinning Superassembled Mesoporous AIEgen-Organosilica Frameworks Featuring Diversified Forms and Superstability for Wearable and Washable Solid-State Fluorescence Smart Sensors.

Flexible optical sensors are widely studied and applied in many fields. However, developing highly stable and washable wearable sensors in optics is still facing significant challenges. Here, we demonstrate an AIEgen-organosilica framework (TPEPMO) hybrid nanostructure-based flexible optical sensor, which is prepared by a two-step co-condensation and electrospinning superassembly process. Organosilica precursors with aggregation-induced emission (AIE) features are covalently linked into periodic mesoporous organosilica (PMO) frameworks with high fluorescent efficiency due to the restriction of intramolecular motion. The three-dimensional space of ordered porous materials provides abundant reaction sites, allowing rapid and sensitive monitoring of analytes. TPEPMOs exhibit good properties as acidic pH fluorescent sensors with a pKa of 4.3. A flexible film is obtained by dispersing TPEPMO nanospheres in a poly(lactic-co-glycolic acid) (PLGA) and polyacrylonitrile (PAN) hybrid fibrous matrix (TPEPMO-CFs) using the electrospinning superassembly technique and is successfully served as an efficient fluorescent probe for the naked eye detection of ammonia gas and HCl vapor by emission changes. The fluorescence of TPEPMO-CFs can be reversed in the presence of volatile acidic/alkaline gas for more than five cycles, exhibiting excellent recyclability. In addition, TPEPMO-CF sensors show excellent washability and long-term photostability (fluorescence was maintained above 94% after washing 10 times). These stimuli-responsive AIEgen-organosilica frameworks featuring diversified forms and superstability for wearable and washable solid-state fluorescence exhibit great potential for smart gas sensors, wearable devices, and solid-state lighting applications.

Toxicity of different zinc oxide nanomaterials and dose-dependent onset and development of Parkinson's disease-like symptoms induced by zinc oxide nanorods.

With the increasing applications in various fields, the release and accumulation of zinc oxide (ZnO) nanomaterials ultimately lead to unexpected consequences to environment and human health. Therefore, toxicity comparison among ZnO nanomaterials with different shape/size and their adverse effects need better characterization. Here, we utilized zebrafish larvae and human neuroblastoma cells SH-SY5Y to compare the toxic effects of ZnO nanoparticles (ZnO NPs), short ZnO nanorods (s-ZnO NRs), and long ZnO NRs (l-ZnO NRs). We found their developmental- and neuro-toxicity levels were similar, where the smaller sizes showed slightly higher toxicity than the larger sizes. The developmental neurotoxicity of l-ZnO NRs (0.1, 1, 10, 50, and 100 µg/mL) was further investigated since they had the lowest toxicity. Our results indicated that l-ZnO NRs induced developmental neurotoxicity with hallmarks linked to Parkinson's disease (PD)-like symptoms at relatively high doses, including the disruption of locomotor activity as well as neurodevelopmental and PD responsive genes expression, and the induction of dopaminergic neuronal loss and apoptosis in zebrafish brain. l-ZnO NRs activated reactive oxygen species production, whose excessive accumulation triggered mitochondrial damage and mitochondrial apoptosis, eventually leading to PD-like symptoms. Collectively, the developmental- and neuro-toxicity of ZnO nanomaterials was identified, in which l-ZnO NRs harbors a remarkably potential risk for the onset and development of PD at relatively high doses, stressing the discretion of safe range in view of nano-ZnO exposure to ecosystem and human beings.

Super-assembled core/shell fibrous frameworks with dual growth factors for in situ cementum-ligament-bone complex regeneration.

The regeneration of periodontal tissue defects remains a clinical challenge due to its complex tissue structure (e.g. periodontal ligament, alveolar bone and cementum) and poor self-healing ability. In situ tissue engineering has emerged as a promising approach that combines frameworks with growth factors that are specifically chosen for the recruitment of endogenous stem cells to the site of injury and to evoke the innate regenerative potential of the body. Herein, a core/shell fibrous super-assembled framework (SAF)-based sequential growth factor delivery system is developed, in which basic fibroblast growth factor (bFGF) and bone morphogenetic protein-2 (BMP-2) are designed to release in a sequential manner to facilitate in situ regeneration of the cementum-ligament-bone complex. The in situ tissue engineering framework (iTE-framework) shows ameliorated physicochemical properties and improved hydrophilicity, with an initial burst release of bFGF in the first few days, followed by a slow and constant release of BMP-2 up to 4 weeks. The iTE-framework shows excellent biocompatibility, significantly promoting the proliferation, migration and osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) in vitro. After implantation in rat periodontal defects, the iTE-framework effectively triggers the recruitment of mesenchymal stem cells (MSCs) to the defect site, significantly promotes the formation of new bones, and facilitates the regeneration of the periodontal ligament and cementum tissue in vivo. Therefore, this sequential delivery system provides a promising therapeutic strategy for cementum-ligament-bone complex regeneration.

Optical-magnetic bifunctional properties and mechanistic insights on upconversion of NaYF4:Yb,Ho,Tm@NaGdF4 with a tunable nanodumbbell morphology.

The energy-upconversion of lanthanide-doped nanoparticles with a core-shell structure can be utilized to enhance and tune optical properties and can generate multifunctionality in a single system. Herein, the core-shell nanoparticles NaYF4:Yb,Ho,Tm@NaGdF4 were prepared by thermally decomposing lanthanide acetylacetonate precursors. Through modifying the molar ratio of the core and shell, nanodumbbell-shaped particles with different sizes and morphologies were precisely synthesized. The formation mechanism and the heterogeneous epitaxial growth process of the nanodumbbell-shaped particles were studied. After coating the shell layer, upconversion luminescence intensities, spectral purity and fluorescence lifetimes were improved. Furthermore, the magnetic performance of the core-shell nanoparticles was characterized. The optical-magnetic bifunctional upconversion core-shell particles with programmable shape and multiple properties provide an ideal platform for the preparation of nanodumbbell-shaped particles and the promotion of upconversion materials for biomedical research.

Efficient Synthesis of Highly Photoluminescent Short Dendritic CdSeS/ZnS Quantum Dots for Biolabeling.

A convenient and efficient approach is reported to synthesize CdSeS with low-cost and low-toxic materials. The influence of the Se/S ratio and reaction time on the photoluminescent properties of CdSeS QDs is investigated through researching the temporal evolution of the absorption and the emission. Following, the high photoluminescent short dendritic green-emitting CdSeS/ZnS QDs are prepared using the method inspired by the successive ion layer adsorption and reaction procedure, which are composed of a CdSeS core and ZnS branches. Transmission electronic microscopy and X-ray diffraction show that the CdSeS/ZnS QDs is in a cubic zinc blende structure. The photoluminescence intensity increase significantly when the ZnS branches form as a result of the charge carriers being confined in the core. The photoluminescence quantum yield of the obtained CdSeS/ZnS core-shell QDs can be up to 90%, which is much higher than that of initial CdSeS QDs (39%). In addition, CdSeS/ZnS QDs have good photoluminescence intensity after they are transferred from organic solvent into aqueous media through ligand replacement using mercaptoacetic acid. Afterwards, the E. Coli O-157 are not only successfully conjugated with CdSeS/ZnS QDs but also present clear images under UV irradiation.