Oxidative polyacrylonitrile nanofiber-based solid-phase microextraction coatings via wrapping strategy for polychlorinated biphenyls determination coupled to GC-MS.

A straightforward approach to fabricating robust and versatile solid-phase microextraction (SPME) fibers is crucial for the extensive research and application of this notable sample preparation technique. Herein, we proposed a strategy for preparation of oxidative polyacrylonitrile (O-PAN) and O-PAN/ZIF-67 nanofiber-based SPME coatings by wrapping an electrospinning membrane on the stainless-steel wire, following with thermal oxidation at 300 °C. The shrinkage of membrane during thermal treatment resulted in the nanofibers being securely affixed to the stainless-steel wire, thereby creating a robust nanofiber-based SPME fiber.

Methyltrimethoxysilane modified tin dioxide microspheres with hydrophobic networks and abundant adsorbed oxygen for efficient solid-phase microextraction of polychlorinated biphenyls.

Methyltrimethoxysilane (MTMS) modified tin dioxide microspheres (MTMS/SnO) were prepared by a facile hydrothermal method and heated reflux reaction strategy. The characterization results indicate that the modification of MTMS induced the formation of a hydrophobic network within the composites, while maintaining abundant adsorbed oxygen species. Subsequently, the MTMS/SnO microspheres were used as a solid-phase microextraction (SPME) coating for the efficient extraction and sensitive determination of trace polychlorinated biphenyls (PCBs) in aqueous solutions coupled to gas chromatography-mass spectrometry.

Monitoring Poly(methyl methacrylate) and Polyvinyl Dichloride Micro/Nanoplastics in Water by Direct Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry.

A simple, sustainable, and sensitive monitoring approach of micro/nanoplastics (MNPs) in aqueous samples is crucial since it helps in assessing the extent of contamination and understanding the potential risks associated with their presence without causing additional stress to the environment. In this study, a novel strategy for qualitative and quantitative determination of MNPs in water by direct solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was proposed for the first time. Spherical poly(methyl methacrylate) (PMMA) and irregularly shaped polyvinyl dichloride (PVDC) were used to evaluate the feasibility and performance of the proposed method.

An asymmetrical flavylium based probe with large Stokes shift and near infrared emission for highly sensitive detecting and visualizing cellular drug induced HS fluctuations.

Hydrogen sulfide (HS) has been recognized as an important gaseous signaling molecule in living systems, and is of great significance in many pathological and physiological processes. Misregulation of endogenous HS is implicated in various diseases in the neuronal, gastrointestinal, circulatory, and endocrine systems. Fluorescent probe with large Stokes shift and near infrared emission, is ideal candidate for imaging applications to prevent excitation scattering, autofluorescence interference, matrix absorption caused signal loss, and sample destruction.

Quantitative Determination of Poly(methyl Methacrylate) Micro/Nanoplastics by Cooling-Assisted Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry: Theoretical and Experimental Insights.

Determinations of micro/nanoplastics (MNPs) in environmental samples are essential to assess the extent of their presence in the environment and their potential impact on ecosystems and human health. With the aim to provide a sensitive method with simplified pretreatment steps, cooling-assisted solid-phase microextraction (CA-SPME) coupled to gas chromatography-mass spectrometry (GC-MS) is proposed as a new approach to quantify mass concentrations of MNPs in water and soil samples. The herein proposed CA-SPME method offers the unique advantage of integrating the thermal decomposition of MNPs and enrichment of signature compounds into one step.

Cellulose Nanocrystals Induced Loose and Porous Graphite Phase Carbon Nitride/Porous Carbon Composites for Capturing and Determining of Organochlorine Pesticides from Water and Fruit Juice by Solid-Phase Microextraction.

Herein, novel, loose, and porous graphite phase carbon nitride/porous carbon (g-CN@PC) composites were prepared by decorating cellulose nanocrystals (CNCs). The characterization results demonstrate that the as-prepared composites presented high specific surface areas, porous structures, and abundant chemical groups, with the modification of CNCs. In view of the unique advantages, g-CN@PC was used as the coating material for the solid-phase microextraction (SPME) of organochlorine pesticides (OCPs) in water and juice samples.

Polyacrylic Acid Functionalized Biomass-Derived Carbon Skeleton with Highly Porous Hierarchical Structures for Efficient Solid-Phase Microextraction of Volatile Halogenated Hydrocarbons.

In this study, polyacrylic acid functionalized N-doped porous carbon derived from shaddock peels (PAA/N-SPCs) was fabricated and used as a solid-phase microextraction (SPME) coating for capturing and determining volatile halogenated hydrocarbons (VHCs) from water. Characterizations results demonstrated that the PAA/N-SPCs presented a highly meso/macro-porous hierarchical structure consisting of a carbon skeleton. The introduction of PAA promoted the formation of polar chemical groups on the carbon skeleton.

Carbon dots derived from peptone as "off-on" fluorescent probes for the detection of oxalic acid.

A simple and rapid microwave heating approach was reported for the preparation of water soluble carbon dots (CDs) using peptone as carbon source with the assistance of ethylenediamine. Several characterization techniques such as transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) were employed to analyze CDs. The optical properties of synthesized CDs were examined by UV-vis and fluorescence spectroscopy.

Wild jujube-based fluorescent carbon dots for highly sensitive determination of oxalic acid.

Fluorescent carbon dots (CDs) were synthesized by a one-step hydrothermal treatment of wild jujube and dl-tryptophan. The structure and properties of the CDs were confirmed by transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet visible absorption spectroscopy, fluorescence spectroscopy and so on. The as-prepared CDs exhibit excellent excitation-independent but pH-dependent (4.

High-throughput profiling volatiles in edible oils by cooling assisted solid-phase microextraction technique for sensitive discrimination of edible oils adulteration.

In this study, a cooling assisted solid-phase microextraction technique (CA-SPME) was proposed and used for identifying volatile and semi-volatile compounds in edible oil innovatively coupled to gas chromatography-mass spectrometry. Compared with regular SPME technique, CA-SPME presented significantly higher extraction efficiencies for analytes in edible oil due to its synergistic effect of heating and cooling. After optimization of the extraction conditions including heating temperature, cooling temperature, extraction time, and added amount of edible oil, thirty-eight, thirty-six, twenty-nine, and thirty-three kinds of compounds in peanut oil, olive oil, canola oil, and soybean oil were successfully identified, respectively, using DVB/CAR/PDMS coating with extraction time of 30 min and edible oil amounts of 20 μL.

Digital finance and innovation inequality: evidence from green technological innovation in China.

Green technological innovation is an overarching approach to tackling environmental pollution, and mitigating the inequality in green technological innovation between regions can contribute to environmental equity. This study measures the inequality in green technological innovation via an index and examines the influence of digital finance on that inequality using data from 285 cities in China from 2011 to 2018. The results are as follows: (1) Digital financial development alleviates the inequality in green technological innovation, and the greater the inequality is, the stronger the effect of digital finance.

Lotus-like Ni@NiO nanoparticles embedded porous carbon derived from MOF-74/cellulose nanocrystal hybrids as solid phase microextraction coating for ultrasensitive determination of chlorobenzenes from water.

Lotus-like Ni@NiO embedded porous carbons (Ni@NiO/PCs) were fabricated by pyrolysis of MOF-74/cellulose nanocrystal hybrids, and used as a solid phase microextraction (SPME) coating for ultrasensitive determination of chlorobenzenes (CBs) from water combined with gas chromatography-mass spectrometry. Owing to its abundant chemical groups, high porosity, and excellent thermal stability, the as-prepared Ni@NiO/PCs presented superior extraction performance compared to commercial SPME coatings. Notably, Ni@NiO/PCs derived from MOF-74/CNC hybrids presented higher extraction efficiencies towards CBs than that derived from pristine CNC and MOF-74 due to the formation of micro/mesopores and more abundant oxygen-containing groups.

Carbon Dot-Decorated Graphite Carbon Nitride Composites for Enhanced Solid-Phase Microextraction of Chlorobenzenes from Water.

In this work, carbon dot-decorated graphite carbon nitride composites (CDs/g-CN) were synthesized and innovatively used as a SPME coating for the sensitive determination of chlorobenzenes (CBs) from water samples, coupled with gas chromatography-mass spectrometry. The CDs/g-CN coating presented superior extraction performance in comparison to pristine g-CN, owing to the enhancement of active groups by CDs. The extraction capacities of as-prepared SPME coatings are higher than those of commercial coatings due to the functions of nitrogen-containing and oxygen-containing group binding, π-π stacking, and hydrophobic interactions.

Core-shell structured FeO/CeO@MnO microspheres with abundant surface oxygen for sensitive solid-phase microextraction of polycyclic aromatic hydrocarbons from water.

Core-shell structured FeO/CeO@MnO microspheres were fabricated and used as solid-phase microextraction coating for determination of polycyclic aromatic hydrocarbons (PAHs) in water samples. XPS spectra demonstrated the generation of abundant surface oxygen on FeO/CeO@MnO microspheres, which provided binding sites for enhancement of analyte extraction. Under optimized conditions, the proposed method presented good linearity in the concentration range 0.

Environmental regulation, import trade, and green technology innovation.

To further clarify the relationship between environmental regulation and green technology innovation and discuss how environmental regulation affects green technology innovation through import trade, this paper analyzes the impacts of environmental regulation and import trade on green technology innovation and the transmission effect of import trade based on panel data for 30 provinces in China for 2008 to 2017. The results show that (1) environmental regulation first plays a role in promoting green technology innovation and then restrains it, and import trade can significantly promote green technology innovation; (2) under the constraints of stronger environmental regulations, import trade has a significantly positive effect on green technology innovation; and (3) environmental regulation can further enhance the technology spillover effects of import trade in regions with high absorptive capacity and regions with high levels of R&D investment. This paper analyzes the impact of environmental regulation on green technology innovation from the perspective of import trade and makes up for the deficiencies of existing research.

Optimized self-immolative near-infrared probe based on hemicyanine for highly specific monitoring thiophenols in living systems.

In this paper, utilizing the same recognition group dinitrophenyl and hydroxyl functional NIR fluorophore hemicyanine, directly-linked probe CyNO and self-immolative probe CyBNO were developed for evaluation of sensing PhSH. Though CyNO was easily synthesized and sensitive to mercapto, the probe CyBNO showed higher selectivity, broader linear range from 1.0 × 10 to 7.

A novel weak acid activated probe for highly selective monitoring selenocysteine in living cells.

Selenocysteine (Sec, pK 5.8) is genetically encoded 21st amino acid into the active site of selenoproteins, which have broad functions relevant to various diseases, tissues or organs and subcellular organelles. However, many selenoproteins involved cellular functions still remains unclear.

A facile cooling-assisted solid-phase microextraction device for solvent-free sampling of polycyclic aromatic hydrocarbons from soil based on matrix solid-phase dispersion technique.

Solvent-free analysis of organic pollutants from a complex matrix has attracted significant attention. In this work, we designed and fabricated a facile cooling-assisted solid-phase microextraction device (CA-SPME) that could be used for the solvent-free extraction of volatile and semivolatile compounds from a complex matrix using a commercial SPME probe. Determination of polycyclic aromatic hydrocarbons (PAHs) from soil samples was carried out to evaluate the performance of the designed CA-SPME device.

Three-dimensional pompon-like Au/ZnO porous microspheres as solid phase microextraction coating for determination of volatile fatty acids from foot odor.

In this study, facile fabrication of three-dimensional (3D) pompon-like gold/zinc oxide (Au/ZnO) porous microspheres by hydrothermal procedure was investigated. These microspheres were utilized as solid phase microextraction (SPME) coating for determination of volatile fatty acids (VFAs) from foot odor coupling with gas chromatography-mass spectrometry (GC-MS). SEM and TEM characterizations showed that as-prepared material was composed of 1D porous nanowires and presented a uniform coating on stainless-steel wire.

Alkaline-promoted regulation of the peroxidase-like activity of Ni/Co LDHs and development bioassays.

Nanozymes' activities could be regulated by a simple and effective pH change in an in situ manner. In this work, for the first time, the peroxidase-like activity of Ni/Co layered double hydroxides (LDHs) was regulated via the alkaline-promoted reaction of fluorogenic substrate homovanillic acid and HO, and a promising tool for pH sensing was developed over the pH range of 8.3-9.

A near-infrared fluorescent probe based on photostable Si-rhodamine for imaging hypochlorous acid during lysosome-involved inflammatory response.

Hypochloric acid (HClO) is mainly distributed in acidic lysosomes of phagocytes and closely associated with numerous physiological and pathological processes, especially inflammatory response. Fluorescent probe has become an important tool for imaging HClO in lysosomes, but suffered from interference from autofluorescence in vivo, phototoxicity to biosamples and photobleaching phenomenon due to their short-wavelength excitation and emission. Unfortunately, up to now, no near-infrared (NIR) lysosome-targetable fluorescent probe has been reported for imaging HClO.

Evaluation of fluorogenic substrates for Ni/Co LDHs peroxidase mimic and application for determination of inhibitory effects of antioxidant.

Nanomaterial-based peroxidase-mimetics are an emerging research field that promises to produce alternatives to horseradish peroxidase for a variety of applications. Generally, some peroxidase-mimetics substrates are used in acidic condition (pH ≤ 7). Then, it is necessary to screen some peroxidase-mimetics substrates suitable for basic condition because that some peroxidase-mimetics leached ions in acidic solution.

One-step analysis of glucose and acetylcholine in water based on the intrinsic peroxidase-like activity of Ni/Co LDHs microspheres.

In the present study, a simple strategy was developed for Ni/Co layered double hydroxides (LDHs) as a substitute for natural peroxidase. The obtained Ni/Co LDHs exhibited ease of preparation, low-cost, and water-solubility; importantly, this material showed high catalytic activity in neutral pH solutions (phosphate buffer, Tris-HCl buffer, and even water). Benefitting from Ni/Co LDHs having a similar pH and temperature with specificity oxidase, such as glucose oxidase, choline oxidase, acetylcholinesterase, etc.

The peroxidase and oxidase-like activity of NiCoO mesoporous spheres: Mechanistic understanding and colorimetric biosensing.

The synthesized NiCoO mesoporous spheres (MS) displayed intrinsic peroxidase and oxidase-like activity were firstly reported. The catalytic mechanism of the oxidase-like activity of NiCoO MS was analyzed in detail using the electron spin resonance (ESR) method. It is found that NiCoO MS could directly oxidize 3,3',5,5'-tetramethylbenzidine (TMB) but did not produce O and ·OH.

Efficient Two-Photon Fluorescence Nanoprobe for Turn-On Detection and Imaging of Ascorbic Acid in Living Cells and Tissues.

Ascorbic acid (AA) serves as a key coenzyme in many metabolic pathways, and its abnormal level is found to be associated with several diseases. Therefore, monitoring AA level in living systems is of great biomedical significance. In comparison with one-photon excited fluorescent probes, two-photon (TP) excited probes are more suitable for bioimaging, as they could afford higher imaging resolution with deeper imaging depth.