A Eu-MOF-Based Fluorescent Sensing Probe for the Detection of Tryptophan and Cu in Aqueous Solutions.

Abnormal tryptophan (Trp) metabolism can be used as an important indicator of chronic hepatitis, paranoia, Parkinson's disease and other diseases. Deficiency or excessive accumulation of Cu can cause diseases such as Wilson's disease and Alzheimer's disease. Eu-based metal-organic framework (Eu-MOF) was successfully prepared for fluorescence sensing of Trp and Cu in an aqueous solution (pH = 7.

Velvet-like carbon nitride as a solid-phase microextraction fiber coating for determination of polycyclic aromatic hydrocarbons by gas chromatography.

In this study, velvet-like carbon nitride (V-g-CN) was prepared from urea aqueous solutions by one-step thermal polycondensation. The V-g-CN material was then characterized using a scanning electron microscope (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometer (FT-IR), and nitrogen adsorption-desorption isotherms. The specific surface area of V-g-CN (60.

A molecular beacon-like Ag nanocluster fluorescence probe for nucleic acid detection.

We have developed a type of low-cost, label-free silver nanocluster molecular beacon-like fluorescence sensor with a DNA template. To detect target DNA with this probe, we use a hairpin DNA sequence based on a "turn-on" strategy. The transformation of hairpin DNA would visibly influence the formation of Ag nanoclusters, such that the stronger fluorescence will be measured with the solution containing target nucleic acids than that without targets nucleic acids.

Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process.

A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.

Coating layered double hydroxides with carbon dots for highly efficient removal of multiple dyes.

Layered double hydroxides (LDHs) and layered double oxides (LDOs) are desirable adsorption materials for printing and wastewater treatment owing to their outstanding anion exchange abilities, abundant active sites, and eco-friendly nature. In this study, a versatile LDO hybrid coated with carbon dots (CDs@MgAl-LDO) was constructed by modifying sodium dodecylbenzene sulfonate on the surface of MgAl-LDH as a carbon precursor, followed by ligand carbonization and hydrotalcite dehydration at 450 °C under N flow. CDs@MgAl-LDO displayed a hexagonal lamellar architecture with a plate lateral size of approximately 500 nm.

Synthesis of 3D magnetic porous carbon derived from a metal-organic framework for the extraction of clenbuterol and ractopamine from mutton samples.

3D magnetic porous carbon (MPCK) was prepared using the metal-organic framework (MOF) MIL-100(Fe) as the carbon precursor by carbonisation and KOH activation strategies. Carbonisation and activation ensured that MPCK possessed excellent structural and thermal stability, strong magnetic responsiveness and high surface area. MPCK was used as an adsorbent for the magnetic solid-phase extraction of clenbuterol and ractopamine from mutton samples.

[Analysis of fatty acids in rice by pseudotargeted metabolomics method based on gas chromatography-mass spectrometry].

A pseudotargeted metabolomics method based on gas chromatography-mass spectrometry (GC-MS) was developed for the analysis of fatty acids in rice. A total of 16 fatty acids were detected in rice. The method was used to identify the difference between fatty acid profiles in rice.

Histone H2A-peptide-hybrided upconversion mesoporous silica nanoparticles for bortezomib/p53 delivery and apoptosis induction.

The design and development of advanced gene/drug codelivery nanocarrier with good biocompatibility for cancer gene therapy is desirable. Herein, we reported a gene delivery nanoplatform to synergized bortezomib (BTZ) for cancer treatment with histone H2A-hybrided, upconversion luminescence (UCL)-guided mesoporous silica nanoparticles [UCNPs(BTZ)@mSiO-H2A]. The functionalization of H2A on the surface of UCNPs(BTZ)@mSiO nanoparticles realized the improvement of biocompatibility and enhancement of gene encapsulation and transfection efficiency.

Design and Synthesis of Ag Nanocluster Molecular Beacon for Adenosine Triphosphate Detection.

This study presents a fluorescence method for detecting adenosine triphosphate (ATP) based on a label-free Ag nanocluster molecular beacon (MB) with high sensitivity. The sensor contains a hairpin-shaped MB, two short single-stranded DNA strands, and T4 DNA ligase. The MB consists of three parts, which are the template DNA sequence for synthesizing Ag nanoclusters at the 5' end, the middle DNA with a hairpin-shaped structure, and the guanine base-rich DNA sequence at the 3' end.

Dispersive solid-phase extraction of bisphenols migrated from plastic food packaging materials with cetyltrimethylammonium bromide-intercalated zinc oxide.

The migration of bisphenols (BPs) can take place from plastic packaging materials into freshly cooked takeaway food, especially at high temperatures. In this study, cetyltrimethylammonium bromide-intercalated zinc oxide (ZnO@CTAB) was developed and used to extract the migration of BPs (bisphenol A and bisphenol AF) from disposable plastic materials to contained food simulates. Several experimental parameters that influence extraction efficiency were investigated.

Fabrication of glucose-derived carbon-decorated magnetic microspheres for extraction of bisphenols from water and tea drinks.

Glucose-derived carbon-decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high-efficiency adsorbent to extract bisphenols in water and tea drinks. The as-prepared carbon-decorated magnetic microspheres had a well-defined core-shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.

Metabolic responses of Saccharomyces cerevisiae to ethanol stress using gas chromatography-mass spectrometry.

Ethanol, as one of the most important biological fuels, is mainly produced by Saccharomyces cerevisiae. But with the accumulation of ethanol, the viability and growth of Saccharomyces cerevisiae is often stressed during fermentation. At present, the reaction mechanism of Saccharomyces cerevisiae to ethanol stress has not been fully elucidated.

Recyclable magnetic NiFeO/C yolk-shell nanospheres with excellent visible-light-Fenton degradation performance of tetracycline hydrochloride.

A photo-Fenton-like reaction was considered as an effective method for wastewater treatment because it could produce more oxidative species such as hydroxyl radicals (˙OH) to accelerate the reaction. In this paper, a NiFe2O4/C (abbr. as NFO/C) yolk-shell nanostructure was synthesized via one-step calcination using polyacrylic acid sodium salt (PAAS) NPs as a template.

Fe-doped HPMoO immobilized on covalent organic frameworks (Fe/PMA@COFs): a heterogeneous catalyst for the epoxidation of cyclooctene with HO.

Covalent organic frameworks (COFs) have arisen as one kind of devisable porous organic polymer that has attracted immense attention in catalytic applications. In this work, we prepared cost-effective imine-based COFs (COF-300, COF-LZU1 and CIN-1) a reaction kettle operated in place of a traditional sealed Pyrex tube. Then, phosphomolybdic acid (PMA) and iron ions were immobilized on the COF supports by impregnation; the resulting frameworks were denoted as Fe/PMA@COFs (Fe/PMA@COF-LZU1, Fe/PMA@CIN-1 and Fe/PMA@COF-300).

Magnetic solid-phase extraction of fluoroquinolones from water samples using titanium-based metal-organic framework functionalized magnetic microspheres.

In this study, a unique core-shell titanium-based metal-organic framework (MOF) functionalized magnetic microsphere was constructed and utilized as magnetic adsorbent for enrichment of five fluoroquinolones from water samples. The received magnetic MOF nanocomposite, denoted as FeO@Cys@MIL125-NH, showed strong magnetic responsiveness, and good hydrophilicity, as well as excellent affinity to the target analytes. Under optimal conditions, the developed magnetic solid-phase extraction (MSPE) method, combined with ultra-high performance liquid chromatography (UPLC), showed good linearity within the studied concentration range, and low limits of detection (0.

Ultrasensitive Biosensor for Detection of Mercury(II) Ions Based on DNA-Cu Nanoclusters and Exonuclease III-assisted Signal Amplification.

This paper describes a novel method for label-free mercury(II) ion detection based on exonuclease III-induced target signal recycling amplification using double-stranded DNA templated copper nanoclusters. The synthesized DNA-Cu nanoclusters were used with exonuclease III loop amplification technology for ultra-high sensitivity detection of mercury(II) ions, which were detected by significantly decreased fluorescence intensity. Under the optimal experimental conditions, there was a clear linear relationship between Hg concentration in the range of 0.

Synergistic apoptotic effects of silibinin in enhancing paclitaxel toxicity in human gastric cancer cell lines.

Gastric cancer (GC) is the 3rd leading cause of tumor‑associated mortality worldwide. The efficacy of paclitaxel, a frequently used GC chemotherapeutic agent, is hindered due to drug resistance, dose‑induced toxicity and adverse side effects. Silibinin, an active compound of a widely consumed dietary supplement, milk thistle extract, has recently been demonstrated to have strong antitumor efficacy in a human GC cell model.

Magnetic solid-phase extraction of tetracyclines using ferrous oxide coated magnetic silica microspheres from water samples.

A novel magnetic solid-phase extraction approach was proposed for extraction of potential residues of tetracyclines (TCs) in tap and river water samples, based on FeO@SiO@FeO magnetic nanocomposite. Characterized results showed that the received FeO@SiO@FeO had distinguished magnetism and core-shell structure. Modified FeO nanoparticles with an ∼5 nm size distribution were homogeneously dispersed on the surface of the silica shell.

Analysis of microcystins using high-performance liquid chromatography and magnetic solid-phase extraction with silica-coated magnetite with cetylpyridinium chloride.

Microcystins (MCs), produced by freshwater cyanobacteria, can be serious water pollutants, so it is important to monitor their concentration in drinking water. We have developed a method for rapid and accurate determination of microcystin levels in environmental water, using magnetic solid-phase extraction and high-performance liquid chromatography with UV detection. The magnetic composite material, which was combined with cetylpyridinium chloride, was prepared by hydrothermal synthesis.

A fluorescence-quenching method for quantitative analysis of Ponceau 4R in beverage.

CdTe quantum dots was synthesized and used to quantitative analysis of Ponceau 4R in solution. With the excitation wavelength of 380nm the emission of CdTe quantum dots was quenched obviously by Ponceau 4R. In order to detect Ponceau 4R in mild condition the influences of fluorescence emission wavelength of CdTe quantum dots, pH value, temperature and reaction time were examined to establish the experimental condition.

Preparation and application of a coated-fiber needle extraction device.

In this study, a needle-trap device with fibers coated with a molecularly imprinted polymer was developed for separation. A number of heat-resistant Zylon filaments were longitudinally packed into a glass capillary, followed by coating with a molecularly imprinted polymer. Then, the molecularly imprinted polymer coating was copolymerized and anchored onto the surface of the fibers.

[Solid-phase extraction based on mesoporous Fe3O4 @ mSiO2 @ Cu2+ magnetic nanoparticles coupled with high performance liquid chromatography for the determination of microcystins in water samples].

Mesoporous magnetic nanoparticles of Fe3O4 @ mSiO2 @ Cu2+ were synthesized by two methods of hydrothermal synthesis and room temperature synthesis. The synthesized mesoporous Fe3O4 @ mSiO2 @ Cu2+ nanoparticles presented uniform sizes, good magnetic properties and specific selectivity. In this work, a novel magnetic solid-phase extraction (MSPE) method based on mesoporous Fe3O4 @ mSiO2 @ Cu2+ nanoparticles (NPs) coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous extraction of trace amount of microcystin-LR (MC-LR) in water samples.

A dual-responsive fluorescence method for the detection of clenbuterol based on BSA-protected gold nanoclusters.

The illegal feeding of clenbuterol (CLB) to domestic animals and the potential harm of it to human health lead an urgent requirement for the efficient detection of CLB, especially in the edible meat. In this paper we reported a new fluorescence method for the detection of trace amount of CLB by using the BSA-protected gold nanoclusters (AuNCs@BSA). Under the excitation of either 280 or 500 nm the emission of AuNCs@BSA was quenched obviously by diazotized CLB, supplying a dual-responsive fluorescence method to detect CLB in aqueous solution.

A fluorescence probe based on biomolecule-stabilized gold nanoclusters for the detection of pazufloxacin mesilate.

In the present study, biomolecule-stabilized Au nanoclusters were demonstrated as a novel fluorescence probe for sensitive and selective detection of pazufloxacin mesilate (PZFX) for the first time. The linear decrease in the fluorescence intensity of Au nanoclusters induced by PZFX allowed for the quantitative detection of PZFX in the range of 0.15 μg/mL to 1 mg/mL, and the detection limit for PZFX was 0.

Needle trap extraction for GC analysis of formic and acetic acids in aqueous solution.

Formic and acetic acids are ubiquitous in the environment, food, and most of the natural products. Extraction of the acids from aqueous solution is required for their isotope analysis by the gas chromatography-isotope ratio mass spectrometry. To this objective, we have previously developed a purge-and-trap technique using the dynamic solid-phase microextraction technology, the NeedlEX.