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Formaldehyde (FA) in food is harmful to human health, an effective detecting tool is highly desired especially for the on-site test. Herein, an amperometric aqueous FA sensor was fabricated by applying Pt–Ag core-shell nanoparticles as electrocatalyst. The well-characterized core-shell nanostructure exhibits high electro-catalytical activity for the detection of FA molecules in solution due to the synergistic effect of bimetallic Pt–Ag nanostructure. The proposed sensor exhibits high FA sensing performance, with a linear detection range from 1 to 100 μM and a limit of detection (LOD) down to 1.0 μM on the optimized conditions. Interferents coexisting in food samples were efficiently minimized by good selectivity. The Pt–Ag nanostructure-based FA sensor keeps catalytical activity for at least 30 d and shows good batch reproducibility. The proposed sensor was applied for the detection of FA in the food samples and satisfactory results were obtained, showing potential for the fast, simple, disposable, and cost-effective FA detecting method for food safety. Associated Products

Quick detection of iron corrosion and scrap metal adsorption, two major threats to human lives and social prosperity, have aroused rising research attention. In this study, an in-situ Fe 2+ indication and adsorption nanofibrous membrane were prepared taking advantage of electrospun technology. Thanks to the synergistic effect of physical and chemical adsorption , a high Fe 2+ adsorption capacity of 218.11 mg/g was achieved, which was verified by scanning electron microscope and simulation results. A distinct color change from white to red, with a board detection range from 1 to 1000 ppm, could be detected within 10 s. Relatively high HOMO-LUMO gap and partially ligand-centered charge transfer (LC), led to the color change of Phen-Fe 2+ fibrous membrane. The binding energy between Fe 2+ and phenanthroline is strong, making it reliable to iron corrosion detection and adsorption in a real-life situation. Associated Products

Currently, the development of polyvalent ions battery systems are still restricted by lacking suitable cathode materials with high energy density and long cycle life attributing to sluggish kinetic mechanism and of polyvalent ions. Herein, an effective inter-layer scaling strategy is proposed by using a simple hydrothermal method . The super layer spacing VS 2 (∼1 nm) cathode dramatically improves electrochemical performance of zinc-ion batteries (ZIBs) and magnesium/lithium hybrid ion batteries (MLIBs). The specific discharge capacities of ZIBs and MLIBs are 450.7 and 488.8 mA h g −1 at current density of 0.1 A g −1 which are much higher than the same type of battery systems. Finally, the diffusion mechanism and the corresponding theoretical model is established by adopting first principles . In brief, the work provides an effective strategy for the large scale application of multivalent and hybrid batteries systems. Associated Products

Many studies have examined the redox behavior of ferrous ions (Fe(II)) sorbed to mineral surfaces. However, the associated hydroxyl radical ( • OH) formation during Fe(II) oxidation by O 2 was rarely investigated at circumneutral pH. Therefore, we examined • OH formation during oxygenation of adsorbed Fe(II) (Fe(II) sorbed ) on common minerals. Results showed that 16.7 ± 0.4–25.6 ± 0.3 μM of • OH was produced in Fe(II) and α/γ -Al 2 O 3 systems after oxidation of 24 h, much more than in systems with dissolved Fe(II) (Fe 2+ aq ) alone (10.3 ± 0.1 μM). However, • OH production in Fe(II) and α -FeOOH/ α -Fe 2 O 3 systems (6.9 ± 0.1–8.3 ± 0.1 μM) slightly decreased compared to Fe 2+ aq only. Further analyses showed that enhanced oxidation of Fe(II) sorbed was responsible for the increased • OH production in the Fe(II)/Al 2 O 3 systems. In comparison, less Fe(II) was oxidized in the α -FeOOH/ α -Fe 2 O 3 systems, which was probably ascribed to the quick electron-transfer between Fe(II) sorbed and Fe(III) lattice due to their semiconductor properties and induced formation of high-crystalline Fe(II) phases that hindered Fe(II) oxidation and • OH formation. The types of minerals and solution pH strongly affected Fe(II) oxidation and • OH production, which consequently impacted phenol degradation. This study highlights that the properties of minerals exert great impacts on surface-Fe(II) oxidation and • OH production during water/soil redox fluctuations. Associated Products

Covalent organic frameworks (COFs) are emergent ideal membrane materials, owing to their pre-designable and well-defined pore structures. However, COFs typically exist as solid powder and are hard to dissolve in most solvent, which renders COFs poor processability in membrane formation. In this study, TpPa-SO 3 H/PAN COF membranes (COFMs) were prepared via counter diffusion method, which is modulated by the pre-assembled two-dimensional (2D) crystalline TpPa-SO 3 H nanosheets as seeding layer. The TpPa-SO 3 H seeding layer regulated the diffusion-reaction behavior of monomers and induced the confined growth of TpPa-SO 3 H COFs, which is favorable for eliminating the intergranular defects inside the TpPa-SO 3 H/PAN COFMs. The thickness of TpPa-SO 3 H seeding layer can be controlled by the amount of TpPa-SO 3 H nanosheets. The charge of the channel wall inside the membrane can fortify the electrostatic repulsion mechanism and facilitate efficient desalination . Under the optimal conditions, the Na 2 SO 4 rejection rate of TpPa-SO 3 H/PAN COFMs can reach 97.4%. Unlike conventional polyamide membranes whose desalination performance usually decreases with the increase of salt concentration , the TpPa-SO 3 H/PAN COFMs preserved superior desalination performance toward high salt concentration up to 10,000 ppm. Associated Products

Polychlorinated naphthalenes (PCNs) are emerging organic pollutants that are harmful to the environment and human health. In this study, a headspace solid-phase-microextraction (HS–SPME)–gas chromatography–tandem mass spectrometry method for the separation and enrichment of PCNs in shrimp was developed and validated. A graphene aerogel was prepared by modifying graphene oxide with a deep eutectic solvent to prevent graphene oxide stacking. As a result, the aerogel had a three-dimensional porous structure, which resulted in easy sorption/desorption for PCNs, and was used as the SPME fiber coating. Next, the experimental parameters for the saponification of the sample matrix and the extraction and desorption of the PCNs were systematically optimized. After optimization, the method showed good linearity ( R 2 ≥0.9968), low limits of detection (0.00983–0.0661 pg g –1 ), and satisfactory recoveries (80.4–108%). Crucially, compared with previously reported methods, this method does not require the use of large amounts of organic reagents or complex operations, giving it the advantages of simplicity, sensitivity, and environmental friendliness. As an example of the practical application of the developed method, the PCNs in river and sea shrimp were quantified. Associated Products

Evaluation of the hydrophobic/hydrophilic interaction individually between the sorbent and target compounds in sample pretreatment is a big challenge. Herein, a smart titanium substrate with switchable surface wettability was fabricated and selected as the sorbent for the solution. The titanium wires and meshes were fabricated by simple hydrothermal etching and chemical modification so as to construct the superhydrophilic and superhydrophobic surfaces. The micro/nano hierarchical structures of the formed TiO2nanoparticles in situ on the surface of Ti substrates exhibited the switchable surface wettability. After UV irradiation for about 15.5 h, the superhydrophobic substrates became superhydrophilic. The morphologies and element composition of the wires were observed by SEM, EDS, and XRD, and their surface wettabilities were measured using the Ti mesh by contact angle goniometer. The pristine hydrophilic wire, the resulting superhydrophilic wire, superhydrophobic wire, and the UV-irradiated superhydrophilic wire were filled into a stainless tube as the sorbent instead of the sample loop of a six-port valve for on-line in-tube solid-phase microextraction. When employed in conjunction with HPLC, four kinds of wires were comparatively applied to extract six estrogens in water samples. The optimal conditions for the preconcentration and separation of target compounds were obtained with a sample volume of 60 mL, an injection rate of 2 mL/min, a desorption time of 2 min, and a mobile phase of acetonile/water (47/53,v/v). The results showed that both the superhydrophilic wire and UV-irradiated wire had the highest extraction efficiency for the polar compounds of estrogens with the enrichment factors in the range of 20–177, while the superhydrophobic wire exhibited the highest extraction efficiency for the non-polar compounds of five polycyclic aromatic hydrocarbons (PAHs). They demonstrated that extraction efficiency was mainly dependent on the surface wettability of the sorbent and the polarity of the target compounds, which was in accordance with the molecular theory of like dissolves like.Keywords:titanium wire;superhydrophobic;superhydrophilic;in-tube solid-phase microextraction;high-performance liquid chromatography Associated Products

Ochratoxin A (OTA) is a harmful mycotoxin, which is mainly secreted by Penicillium and Aspergillus species. In this work, an electrochemical aptasensor is presented for OTA detection based on Au nanoparticles (AuNPs) modified zeolite imidazolate frameworks (ZIFs) ZIF-8 platform and duplex-specific nuclease (DSN) triggered hybridization chain reaction (HCR) signal amplification. G-quadruplex-hemin assembled HCR nanowire acted as a nicotinamide adenine dinucleotide (NADH) oxidase and an HRP-mimicking DNAzyme. Besides, thionine (Thi) was enriched as a redox probe for signal amplification in this pseudobienzyme electrocatalytic system. Under the optimal conditions, the analytical response ranged from 1 to 10 7  fg ml −1 with a detection limit of 0.247 fg ml −1 . Furthermore, the aptasensor was proven to be applied in real wheat samples with a recovery between 96.8 and 104.2%, illustrating the potential prospects in practical detection. Associated Products

Liver fibrosis (LF) is a major disease that threatens human health. Hepatic stellate cells (HSCs) contribute directly to LF via extracellular matrix (ECM) secretion. Moreover, RXRα is an important nuclear receptor that plays a key regulatory role in HSC activation. Meanwhile, microRNAs (miRNAs) have been identified as significant regulators of LF development. In particular, miR-654-5p is involved in cellular migration and proliferation, and via bioinformatics analysis, has been identified as a potential factor that targets RXRα in humans and in mice. However, the precise relationship between miR-654-5p and RXRα in the context of LF, remains unknown and is the primary focus of the current study. To establish in vitro activated cell model human primary HSCs were cultured in vitro and LX-2 cells were stimulated with recombinant human TGF-β1. mRNA and protein levels of RXRα, miR-654-5p and fibrogenic genes were compared in quiescent and activated HSCs. Moreover, after transfected with miR-654-5p mimics, the expression changes of above related genes in LX-2 cells were estimated. Meanwhile, cell proliferation and apoptosis were detected in miR-654-5p overexpressed LX-2 cells. Simultaneously, the targeted binding between miR-654-5p and RXRα was verified in LX-2 cells. Carbon tetrachloride (CCl 4 )-induced mouse model with liver fibrosis was use to research the role of the miR-654-5p in vitro . Our results show that miR-654-5p expression levels increased in activated human HSCs and TGFβ-treated LX-2 cells. Moreover, miR-654-5p mimics markedly promoted LX-2 cell proliferation while inhibiting their apoptosis. Accordingly, the expression levels of RXRα are decreased in activated HSCs and LX-2 cells. Additionally, dual-luciferase reporter assay results reveal direct targeting of RXRα by miR-654-5p. Similarly, in vivo miR-654-5p overexpression aggravates LF in mice that are intraperitoneally injected with CCl 4 . Taken together, our findings elucidated a novel molecular mechanism with potential use for treatment of LF. Associated Products

Hordein nanoparticles have been successfully fabricated to encapsulate EGCG. The present study aimed to investigate the effect of hordein nanoparticles encapsulation on antioxidant activity, storage stability and in vitro release of EGCG. The antioxidant activities of EGCG before and after encapsulation by hordein nanoparticles had no significant difference. The 28-day storage experiments indicated that EGCG-hordein nanoparticles had a good storage stability in terms of average diameter and zeta potential. Meanwhile, the stability of EGCG was significantly improved by hordein nanoparticles encapsulation. The remaining amount of encapsulated EGCG was 1.31-fold and 1.52-fold higher than that of free EGCG at 4 °C and 25 °C, respectively. The release study in the simulated gastric or intestinal fluids suggested that hordein nanoparticles could slow down the release of EGCG in the simulated gastric or intestinal fluids. These results showed that encapsulation of EGCG using hordein nanoparticles could be a promising approach to improve its stability. Associated Products

Fluorescent carbon dots (CDs) with the long-wavelength emission have received increasing attention due to their promising application prospects in the biological field. The synthesis of CDs with long wavelength emission mainly focuses on the high temperature method, but the room temperature synthesis is still rarely studied. Herein, a simple room temperature strategy is developed for the preparation of orange-emitting CDs (O-CDs) by Schiff base crosslinking reaction between methyl- p -benzoquinone and triethylenetetramine. The proposed O-CDs show a strong excitation-dependent emission with a relative quantum yield of about 6.56%. Because of the strong inner filter effect, O-CDs can be well applied for the highly-sensitive detection of vitamin B12 (VB12). The intensity ratio ( F / F 0 ) of O-CDs is linear against the concentration of VB12 from 50 nM to 200 μM with a low detection limit of 10 nM. Therefore, the obtained O-CDs nanoprobes provide a promising platform for pharmaceutical analysis applications. Associated Products

Octa(dimethylethoxysiloxy) POSS (ODES) was synthesized successfully and used as the novel curing agent to prepare RTV silicone rubber (SROD) with outstanding mechanical properties and thermal stability. Compared with the silicone rubber cross-linked by tetraethoxysilane (SRTE), the novel RTV silicone rubber using octa(dimethylethoxysiloxy) POSS as a cross-linker had better mechanical, thermal, and optical properties. The highest tensile strength of SROD reached 1.26 MPa, which is three times that of SRTE. Besides, the decomposition temperature of 10% weight loss reached 507.7°C, exceeding that of SRTE by nearly 150°C. In addition, it was remarkable that due to the good compatibility of ODES with the silicone rubber matrix, the series of SROD showed good transmittance, greater than 87%. The thermal decomposition process of SROD was investigated by TGA coupled with real-time FTIR, and the results revealed the rigid structure and large steric hindrance of ODES that efficiently blocked the “backbiting” of the polysiloxy chains and delayed the end-induced ring decomposition, and consequently, improved the thermal stability of SROD significantly. Associated Products