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Mono-/diboron complexes with saddle-shaped molecular conformations were synthesized from porphyrins(2.1.2.1). The boron complexes have unique structure-dependent photophysical properties: (a) monoboron complexes 2a and 2b are not emissive in solution and the solid state, (b) diboron complex 3a shows red emission in toluene, and (c) diboron complex 3b shows aggregation-induced emission (AIE) in the deep-red region due to intermolecular secondary interactions (F-π). This is the first case of a boron porphyrinoid complex that shows AIE emission in the deep-red region in decades.

Nanotechnology is rapidly sweeping through all the vital fields of science and technology such as electronics, aerospace, defense, medicine, and catalysis. It involves the design, synthesis, characterization, and applications of materials and devices on the nanometer scale. At the nanoscale, physical and chemical properties differ from the properties of the individual atoms and molecules of bulk matter. In particular, the design and development of silica nanomaterials have captivated the attention of several researchers worldwide. The applications of hybrid silicas are still limited by the lack of control on the morphology and particle size. The ability to control both the size and morphology of the materials and to obtain nano-sized silica particles has broadened the spectrum of applications of mesoporous organosilicas and/or has improved their performances. On the other hand, adsorption is a widely used technique for the separation and removal of pollutants (metal ions, dyes, organics,...) from wastewater. Silica nanoparticles have specific advantages over other materials for adsorption applications due to their unique structural characteristics: a stable structure, a high specific surface area, an adjustable pore structure, the presence of silanol groups on the surface which allow easy modification, less environmental harm, simple synthesis, low cost, etc. Silica nanoparticles are potential adsorbents for pollutants. We present herein an overview of the different types of silica nanoparticles going from the definitions to properties, synthetic approaches and the mention of potential applications. We focus mainly on the recent advances in the adsorption of different target substances (metal ions, dyes and other organics).

Novel 24π antiaromatic and 26π aromatic

Cellulose acetate membrane (CAM) has become one of the most widely used membrane materials by virtue of stability and hydrophilicity. In this work, to achieve the aim of selective recognition and separation of drug molecule shikimic acid (SA), an effective recognition tactics was proposed by combining boron affinity technology with surface imprinting strategy based on cellulose acetate membrane with low price and biocompatibility. The supporting CAM material was prepared through the phase inversion technique by continuous adjustment of different factors including solvent type and kinds of pore-forming agents, and the optimal CAM with multistage structure and highly porosity was applied for the imprinting of SA. Then the imprinted polymer membrane (MIPs-CAM) was developed via boron affinity surface imprinting polymerization. Various methods (FT-IR, UV-vis, SEM, XPS, AFM and TGA) were used to characterize the structure, morphology, elemental composition, surface roughness and thermal property of the obtained membrane. The as-prepared MIPs-CAM showed homogeneous and abundant imprinted layer, good thermal stability. The batch adsorption results showed that the MIPs-CAM had fast adsorption kinetics, specific recognition ability, and the adsorption capacity could obtain 63.598 mg g

As a very promising biofuel or fuel additive, the synthesis of 5-ethoxymethylfurfural (EMF) directly from renewable carbohydrates is an important biomass transformation process. Herein, a novel bif...

Satellite remote sensing and numerical models are widely used to estimate large-scale variations in ocean carbon export, but the relationship between export efficiency (e-ratio) of sinking organic carbon out of the surface ocean and its drivers remains poorly understood, especially in the Southern Ocean. Here, we assess the effects of temperature and primary productivity on e-ratio by combining particulate organic carbon export flux from in situ measurements during 1997–2013, environmental parameters from satellite products, and outputs from ocean biogeochemical models in the Southern Ocean. Results show that “High Productivity Low E-ratio” (HPLE) is a common phenomenon in the Subantarctic Zone and the Polar Frontal Zone, but not the Antarctic Zone. The e-ratio shows little dependence on temperature below 6 °C. Our results support the hypothesis that the HPLE phenomenon is due to the large contribution of non-sinking organic carbon. Both temperature and ballast minerals play less important roles in controlling e-ratio than ecosystem structure at low temperatures. These findings suggest that non-sinking organic carbon, ecosystem structure, and region-specific parameterizations of e-ratio are key factors to quantify the carbon export in the Southern Ocean.

Nitrogen-doped carbon materials have attracted enormous interest in catalysis owing to their outstanding catalytic performance. In this work, nitrogen-doped carbonaceous catalysts (NCC) supported on inexpensive and naturally abundant halloysite nanotubes were successfully synthesized via precipitation polymerization, calcination, and sulfonation processes. The physical and chemical properties of the obtained catalysts were systematically characterized by different methods. The results indicated that NCC catalysts had mesoporous structures, excellent thermostability and acid-base bi-functional active sites. One-pot synthesis of 5-hydroxymethylfurfural (HMF) from glucose was performed to investigate the synthesized NCC catalysts. Benefiting from the synergistic effects of the acid-base bi-functional active sites, the highest HMF yield (62.8%) was achieved in an isopropanol-mediated DMSO system under optimal conditions. Moderate to excellent yields of HMF were also obtained from one-pot conversions of other carbohydrates, including inulin, sucrose, cellobiose, maltose and starch, with our developed catalytic system. The one-pot production of HMF from cellulose was also smoothly processed by the NCC bi-functional catalyst in an IL-based system. This work has developed a versatile strategy for designing nitrogen-doped carbonaceous catalysts that can be employed for the direct transformation of renewable carbohydrates to platform chemicals.

Inspired by the mastoid structure of the lotus leaf and the robust layered structure of the nacre, a novel nacrelike graphene oxide-calcium carbonate (GO-CaCO3) hybrid mesh with superhydrophilic and underwater superoleophobic property was prepared for the first time, via a facile, economical, and environmentally friendly layer-by-layer (LBL) self-assembly method using commercially available stainless steel mesh (SSM) as a ready-made mask. Interestingly, GO nanosheets played a threefold role, regulating the growth of CaCO3 nanocrystals between the GO interlamination for constructing a "brick-and-mortar" structure, improving the interface stability via coordination assembly onto SSM, and creating strong hydration derived from rich oxygen-containing functional groups. The surface hydrophilicity and hierarchically micro/nanoscale structure of GO-CaCO3 artificial pearls imbed on the SSM, contributing to outstanding superhydrophilicity and underwater superoleophobicity. The biomimetic hybrid mesh exhibited a strong mechanical property with a Young's modulus of 25.4 ± 2.6 GPa. The optimized hybrid mesh showed a high separation efficiency of more than 99% toward a series of oil/water mixtures with high flux. The low oil-adhesion force, high fatigue-resistance, chemical stability (acid/alkali/salt resistance), and excellent recycling performance enlighten the great prospects of GO-based nacrelike material for application in oily wastewater treatment.

Metal-organic frameworks (MOFs) featured with flexible design and versatile properties are finding increasing applications. In particular, integrating multiple functions into one framework can bring them improved detection efficiency towards various analytes. Herein, for the first time, a Fe-Zr bi-metal-organic framework (UiO-66(Fe/Zr)-NH2) with three functions (intrinsic fluorescence, peroxidase-mimicking activity, and specific recognition) is designed to establish a ratiometric fluorescent platform for high-performance phosphate ion (Pi) sensing. The use of a fluorescent organic ligand endows the MOF material with a strong intrinsic fluorescence at 435 nm. The presence of Fe3+/Fe2+ nodes offers good enzyme-like capacity to catalyze the o-phenylenediamine (OPD) substrate to fluorescent OPDox (555 nm), which then quenches the intrinsic fluorescence of UiO-66(Fe/Zr)-NH2 due to the inner filter effect. The Zr4+ nodes in the MOF material act as selective sites for Pi recognition. When Pi exists, it specifically adsorbs onto UiO-66(Fe/Zr)-NH2 and decreases the latter's peroxidase-mimetic activity, resulting in the less production of fluorescent OPDox. As a consequence, the intrinsic fluorescence of UiO-66(Fe/Zr)-NH2 at 435 nm is restored, and the signal from OPDox at 555 nm is reduced inversely. With the ratiometric strategy, efficient determination of Pi with outstanding sensitivity and selectivity was realized, giving a detection limit down to 85 nM in the concentration range of 0.2-266.7 μM. Accurate measurement of the target in practical water matrices was also validated, indicating its promising application for Pi analysis in environmental and other fields.

In recent years, there has been rapid growth of enzyme-mimicking catalytic nanomaterials (nanozymes). Compared with biological enzymes, nanozymes exhibit several superiorities, including robust activity, easy production, and low cost, which endow them with promising applications in biochemical analysis. As an emerging member of nanozymes, metal-organic framework (MOF) nanozymes are attracting growing attention because of their composition and structural characteristics. Rationally designing MOFs with enzyme-like catalytic ability is opening up a new avenue for biochemical detection. In this Feature Article, we summarize the latest developments of MOF nanozymes and their applications in biochemical sensing. First, the types of nanozymes derived from MOFs are categorized, and effective strategies to improve the weak activity inherent in MOF nanozymes are introduced. Then, the multi-functionalization of MOFs with enzyme mimic activity and other attractive properties is emphasized. After that, the typical applications of MOF nanozymes in the detection of various analytes are rigorously reviewed. Finally, the current challenges and some development directions in this field are discussed. It is believed that the versatile nature of MOFs will bring a bright future for MOF nanozymes in biochemical analysis.

Three copper dibenzoporphyrin(2.1.2.1) complexes having two dipyrromethene units connected through

Highlights: • Ultrahigh seawater DMS levels (>40 nM) were detected near the Antarctic Peninsula. • Ultrahigh DMS was only found in waters of algal bloom and abundant microzooplankton. • Grazing of abundant microzooplankton possibly cause the ultrahigh seawater DMS. Oceanic dimethylsulfide (DMS) is hypothesized to impact cloud formation and consequently the solar radiation budget of Earth's surface. Ultrahigh seawater DMS concentrations, up to hundreds of nM, have been observed in the Southern Ocean, attributing to concurrent high phytoplankton biomass. However, phytoplankton biomass cannot fully explain the mechanism leading to those extreme values. Herein, measurements, including seawater DMS concentrations and other biological and environmental parameters, were collected in the water column during the austral summer of 2015–2016 at the tip of the Antarctic Peninsula. Notably, large-scale ultrahigh seawater DMS concentrations (up to 85.2 nM and generally above 40 nM in the upper layer) was observed only in areas with co-existing phytoplankton blooms and abundant microzooplankton (indicated by ciliates, whose abundance and biomass were above 1000 ind L-1 and 2 μg L-1, respectively), implying that the grazing of abundant microzooplankton possibly causes the ultrahigh seawater DMS concentrations during the bloom seasons in the Southern Ocean.

Description, Neutrophil-derived exosomes induce tumor cell apoptosis by delivering cytotoxic proteins and activating caspase signaling pathway., Neutrophils are the most abundant innate immune cells in human circulation; however, their derived exosomes have been rarely studied for tumor treatment. Here, we reported that exosomes from neutrophils (N-Ex) induce tumor cell apoptosis by delivering cytotoxic proteins and activating caspase signaling pathway. In addition, we decorated N-Ex with superparamagnetic iron oxide nanoparticles (SPIONs) to achieve higher tumor-targeting therapeutic effect. We further fabricated exosome-like nanovesicles from neutrophils (NNVs) at high yield. Compared with liposome-loaded doxorubicin (DOX) and natural NNVs, DOX-loaded NNVs show an improved inhibition of tumor cell proliferation. Moreover, DOX-loaded, SPION-decorated NNVs selectively accumulate at the tumor sites under an external magnetic field, effectively restraining tumor growth and extensively prolonging the survival rate in mice. Overall, a simple and effective method to engineer N-Ex and NNVs at clinical applicable scale was developed, which enables the efficient and safe drug delivery for targeted and combined tumor therapy.

Quick and precise recovery of palladium (Pd) from electronic waste remains a serious task, owing to the strong acid and complexity of chemical compounds in leachate. Here, bioinspired construction of magnetic nano stirring rod with radially aligned dual mesopores and abundant 8-aminoquinoline (MNSR-DM-AQ) is proposed for selective and rapid extraction of Pd(II) from highly acidic sample solutions. Benefit from the unique dual mesoporous (12.4 nm and 3.6 nm) and the stirring motion under an external magnetic field, MNSR-DM-AQ possesses enhanced adsorption capacity and kinetics, achieving 11.62 mg g

Hemoperfusion is a powerful and yet simple method for lead poisoning treatment, but creation of safe and effective sorbents with excellent selectivity remains a real challenge. To address this, we here construct 2D nanosheet sorbents (BM-SH) through metastable emulsion droplets and subsequent two-step grafting polymerization for efficient blood lead removal in vitro. Metastable emulsion droplets endow typical nanosized sheet-like structure (thickness of 30 nm) and relatively round shape. The consecutive two grafting processes using hydroxyethyl methacrylate (HEMA) and L-cysteine monomer (D-SH) provide BM-SH with a high density of accessible binding sites towards lead ions (Pb

The first example of monovalent and bimetallic porphyrins(2.1.2.1), the rhodium(I) complex of porphyrin(2.1.2.1), was readily obtained under controlled conditions. The coordinated rhodium(I) drastically influenced the molecular structure and optical and electronic properties. Our results clearly demonstrate that porphyrin(2.1.2.1) could be developed as a new binucleating ligand for the fabrication of bimetallic complexes.

Monitoring of pesticide residues in food and environmental matrices is undoubtedly crucial to guarantee food safety and ecological health, yet how to realize their sensitive and convenient detection is still challenging. Herein, we propose an all-in-one test strip that elaborately integrates bioenzyme, nanozyme and chromogen together, and achieve the highly sensitive and convenient sensing of pesticide residues assisted by a smartphone. A sequential self-assembly strategy was first explored to acquire an integrative bioenzyme-nanozyme-chromogen assembly, and then the assembly was confined in a biocompatible hydrogel to construct the test strip. Thanks to both the proximity and confinement effects, a ∼1.2-fold improvement of the cascade catalytic efficiency was gained to benefit high-sensitivity detection. More importantly, since all the sensing elements, including target recognition units and signal amplification modules, were rationally integrated in the test strip, detection operation was significantly simplified, making it possible for in-field rapid analysis. Besides, the microenvironment provided by the alginate hydrogel carrier endowed the test strip with an excellent sensing stability. By taking paraoxon as a typical pesticide, high-performance detection of the target was accomplished via the smartphone-assisted all-in-one test strip. Moreover, the test strip was successfully applied for paraoxon detection in various real samples and exhibited good correlations with commercial kits, demonstrating its great prospect for practical applications. Our work not only offers a new tool for the high-sensitivity and convenient monitoring of pesticide residues, but will also inspire the development of efficient multi-enzyme sensing platforms.

The great threat of pesticide residues to the environment and human health has drawn widespread interest to explore approaches for pesticide monitoring. Compared to commonly developed single-signal pesticide assays, multi-mode detection with inherent self-validation and self-correction is expected to offer more reliable and anti-interference results. However, how to realize multi-mode analysis of pesticides still remains challenging. Herein, we propose a dual-mode fluorescence and colorimetric method for pesticide determination by integrating stimulus-responsive luminescence with oxidase-mimetic activity into cerium-based coordination polymer nanoparticles (CPNs(Ⅳ)). The CPNs(Ⅳ) exhibit good oxidase-like activity of catalyzing the colorless 3,3',5,5'-tetramethylbenzidine (TMB) oxidation to its blue oxide, offering a visible color signal; by employing acid phosphatase (ACP) to hydrolyze ascorbic acid 2-phosphate (AAP), the generated ascorbic acid (AA) can chemically reduce the CPNs(Ⅳ) to CPNs(Ⅲ), which exhibit a remarkable fluorescence signal but lose the oxidase-mimicking ability to trigger the TMB chromogenic reaction; when pesticides exist, the enzymatic activity of ACP is restrained and the hydrolysis of AAP to AA is blocked, leading to the recovery of the catalytic TMB chromogenic reaction but the suppression of the fluorescence signal of CPNs(Ⅲ). According to this principle, by taking malathion as a pesticide model, dual-mode 'off-on-off' fluorescence and 'on-off-on' colorimetric detection of the pesticide with good sensitivity was realized. Excellent interference-tolerance and reliability were verified by applying it to analyze the target in real sample matrices. With good performance and practicability, the proposed dual-mode approach shows great potential in the facile and reliable monitoring of pesticide residues.

Knowledge about organic carbon loadings (ratio of sedimentary organic carbon (SOC) content to specific surface area (SSA)) and the fate of organic carbon (OC) is critical to understand the marine carbon cycle. We investigated the variations in the patterns of OC loadings and the preservation capacities of sedimentary OC in the Yap Trench and other marine environments. The average OC loading in sediment cores from various marine environments decreases with increasing water depth at a rate of ~0.06 mg OC/(m2·km) (R2 =0.23, P

In this work, a novel label-free hypochlorite amperometric sensor based on the direct oxidation of benzeneboronic acid pinacol ester (BAPE) induced by hypochlorite was developed. 4-Aminophenylboronic acid pinacol ester (ABAPE) chemically bonded to functionalized multi-walled carbon nanotubes (f-MWCNTs) was employed to recognize the hypochlorite species. In nearly neutral solutions, the ABAPE probe was able to provide a distinct oxidation signal at approximately 0.65 V vs. Ag/AgCl. When hypochlorite was added, it reacted with ABAPE rapidly to form a stable hydroxyl derivative, resulting in a significant decrease of the current at 0.65 V. Therefore, the hypochlorite target could be detected by recording the reduced oxidation signal of ABAPE. Under optimized conditions, the fabricated sensor offered linear amperometric responses for the target in the concentration ranges of 0.01–0.1 mM and 0.1–1 mM, providing a limit of detection down to 5.3 μM based on S/N = 3. The presence of common anions, including carbonate, sulfate, nitrate, and halide ions, had no obvious effects on the selective determination of hypochlorite. The amperometric sensor also exhibited excellent accuracy and precision in monitoring the hypochlorite level in tap water. These results suggest that the new sensor has great promise for use in various fields such as water pollution control, environmental monitoring, and food safety.

There is a pressing need to develop Janus-like magnetic molecularly imprinted polymers (J-SNs-MMIPs) nanoplatforms that integrate recognition elements and fast separation for specific adsorption and separation of 2′-deoxyadenosine (dA). In this work, the Janus silica nanosheet (J-SNs) with a hydrophobic surface (capped with 3-chloropropyl groups) and a hydrophilic surface (capped with amino-groups) was firstly fabricated by crushing Janus composite hollow spheres resulting from self-organized sol-gel process at amphiphilic emulsion interface. Subsequently, the imprinted polymers using dA as template molecule and synthesized 5-(2-Carbomethoxyvinyl)-2′-deoxyuridine (AcrU) as functional monomer were grafted onto the hydrophobic surface of J-SNs by activators regenerated electron transfer atom transfer radical polymerization (ARGET ATRP). Finally, carboxyl modified Fe3O4 particles were attached onto the hydrophilic surface of as-prepared J-SNs-MIPs via the condensation reaction between amino and carboxyl groups. The J-SNs-MMIPs displayed the ability to specifically recognize and fast separate dA, whereas no imprinting effect was observed for 2′-deoxyguanosine (dG) or deoxycytidine (dC) or 5′-monophosphate disodium salt (AMP). And the formed hydrogen bonds between complementary base of AcrU and adenine base on the dA enhance the affinity. Moreover, the equilibrium time was 70 min, and the maximum monolayer adsorption was calculated to be 61.22 μmol g−1 at 25 °C. By evaluating the selective recognition of dA from spiked human urine samples, the J-SNs-MMIPs could be used for selective separation and analysis of target dA in complex biological samples.