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Finally, the method was applied to four environmental water samples of different origin. Relative recovery values ranging from 91 to 120% highlighted that the matrices under consideration do not affect the extraction process. This work constitutes the first time in which nitro musks compounds were selectively extracted by taking advantage the high potential that magnetic-based microextraction techniques offer, specially SBSDME.With a dramatic increase in the incidence of obesity, it is significant to screen lipase inhibitors from traditional herbal medicines as drugs to treat obesity. Lipase inhibitors currently used to treat obesity possess the defects of toxicity and off-target effects. Thus, there is an urgent need to explore more safe, effective and targeted anti-obesity drugs from traditional herbal medicines. In this work, amino functionalized magnetic cellulose microsphere was employed as a novel support to immobilize lipase through covalent bonding. Characterizations from fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction demonstrated the successful preparation of the support. In comparison with the free lipase, the immobilized lipase manifested the excellent properties of a wider range for pH and temperature endurance, better pH, thermal, storage stability and reusability. Through investigating the kinetics performances of the immobilized lipase, the Michaelis-Menten constant was calculated to be 2.05 mM and its inhibition constant for orlistat was ascertained to be 40.74 μM. Eventually, the established strategy was applied to screen lipase inhibitors from 7 traditional herbal medicines and Crataegus pinnatifida Bunge was screened out due to its significant lipase inhibitory activity. To sum up, our newly established method not only developed a platform for efficiently discovering novel anti-obesity drugs from traditional herbal medicines, but also laid a solid foundation for successfully exploring undiscovered medicinal value of the traditional herbal medicines.One-pot magnetic separation of uranium (U) in seawater and groundwater samples has been made possible by synthesizing phosphoramidate functionalized Ag coated citrate-Fe3O4 nanoparticles (NPs). The magnetic saturation value of these functionalized NPs is 27.1 emu g-1. The synergistic extraction mechanism of U(VI) ion by the surface-modified phosphoramidate and citrate molecules make these NPs highly selective towards U(VI). The adsorption kinetics follows a pseudo-second-order model and the adsorption isotherm fits successfully to the Langmuir adsorption model. The functionalized NPs show quantitative extraction efficiency in the pH range of 6.5-8 with a maximum loading capacity (Qm) of 108.7 mg g-1. The equilibration time required by these functionalized NPs to attain the Qm value is 120 s. The recycling of these NPs can be done up to 5-6 times with 1.0 mol L-1 of Na2CO3 or NH4OH for quantitative extraction of U(VI). These functionalized NPs show high resilience towards large number of naturally abundant metal ions.In this work, a highly sensitive colorimetric paper-based optode for the determination of thiocyanate in urine samples was developed for the first time. The cocktail solution of the optode was composed of 5,10,15,20-tetrakis(4-octyloxyphenyl)porphyrin cobalt(II) complex (L), tridodecylmethylammonium chloride (TDMACl), 2-nitrophenyl octyl ether, and polyvinyl chloride as an ionophore, an ion exchanger, a plasticizer, and a polymer, respectively. The paper-based optode responded to thiocyanate by increasing the blue component in the RGB index and a visible change, with the naked-eye, of the optode color from pink to green was observed. From the central composite design, the optimized conditions that yielded the highest sensitivity were 4.70 mmol/kg TDMACl and 13.75 mmol/kg L. The developed optode sensor was highly selective and responded to thiocyanate over other anions, with a working range of 0.001-5 mM and with a coefficient of determination (R2) of 0.9915. The limits of detection using naked-eye and camera were determined to be 50.0 μM and 1.26 μM, respectively. In addition, the LOD and LOQ estimated from the standard deviation of the blank were 0.65 and 1.87 μM, respectively. Furthermore, this sensor was successfully applied to the detection of thiocyanate in urine samples from non-smokers and smokers. The results were in good agreement with the standard ion chromatography (IC) technique. This developed paper-based optode sensor was simple, low-cost, portable, and easy to use as a sensing device without any complicated instrument.A simple method based on the use of inductively coupled plasma mass spectrometry in single particle mode (SP-ICP-MS) has been proposed, for the first time, for the study of platinum nanoparticles (PtNPs) in complex clinical matrices such as human urine and blood serum. Critical parameters for signal acquisition were optimized to achieve a correct and simultaneous sizing and counting (particle-based in particles L-1 and mass-based in ng L-1) of 50 and 70 nm PtNPs. Different reagents, as tetramethylammonium hydroxide (TMAH) and/or Triton X-100, and concentrations have been tested to ensure an adequate stabilization and extraction of PtNPs. Finally, TMAH at 1% is demonstrated to be the best reagent to extract the NPs guaranteeing their integrity. No heating or any additional treatment was required, which allows sample preparation, and the overall process, to be simple and fast. Good precisions for size (2% RSD) and particle number and mass concentrations ( less then 1% RSD), and limits of detection of 21.6 nm and 1.9 × 105 particles L-1 were reported. The influence of matrix on the determination of PtNP sizes and number- and mass-based concentrations was evaluated. Particle sizes were in all cases in accordance with values determined by TEM or SEM, whereas recoveries of PtNPs in terms of concentration ranged between 92 and 101%. The stability of PtNP characteristics after 24 h was specifically studied in human urine spiked with PtNPs. Statistically significant differences were only reported for the particle number concentrations of 50 nm PtNPs in female urine samples. The present work will be relevant to understand the behaviour of PtNPs in body fluids and to take appropriate actions in future (pre)clinical trials.Fluorescent silicon nanoparticles (Si NPs) are of great interest as they are free of heavy ions. However, most of Si NPs exhibit blue or green emission, while orange or red-emitting Si NPs are required for an extensive range of applications. Copper ion (Cu2+) and l-methionine (L-Met) detection is critically valuable point since their abnormal level is an indicator of various diseases. In this work, we illustrate an "off-on" method for sensitively and selectively determination of Cu2+ and L-Met using Si NPs as fluorescent probe. The Si NPs emitting orange fluorescence with the quantum yield of 2.23% were prepared via one and easy step of hydrothermal treatment of 3(2-aminoethylamino) propyl (dimethoxymethylsilane) (AEAPDMMS) and 2-aminophenol as precursors. The fluorescence of Si NPs was quenched in the presence of Cu2+ due to the strong metal-ligand coordination and electrostatic interactions between the large amount of amino and hydroxyl groups on the surface of Si NPs and Cu2+. Surprisingly, the resulted non-fluorescent Si NPs-Cu2+ complex displayed a fluorescence "turn-on" toward L-Met, due to the competitive coordination of Cu2+ between L-Met and Si NPs which leads to the unique "off-on" response to L-Met after the release of free Si NPs. The as-proposed approach is fast, simple, low cost and environmental-friendly. More importantly, it has been applied in the determination of Cu2+ and L-Met in water and urine samples, respectively with satisfactory recoveries. Furthermore, the approach could detect Cu2+ and L-Met with detection limit of 0.012 μM and 0.07 μM, which are lower than the level of Cu2+ in drinking water and of L-Met in human urine sample (maximum ~20 μM and ~5.9 μM, respectively).A thermally responsive hybrid poly(NIPAm-b-BVIm[FcCOO])-rGO composed of block co-polymer poly(NIPAm-b-BVImBr), reduced graphene oxide (rGO) and electroactive anions was designed and synthesized to achieve electroactive functionality. It is the polymeric ionic liquids (PILs) segment in the block co-polymer that integrated the three different components into a whole hybrid. Such segment of PILs could not only promote the modification of polar PNIPAm onto the non-polar rGO by cation-π interaction, but also realize the immobilization of ferrocenecarboxylate anion (FcCOO-) via anion-exchange reaction. The PNIPAm moiety endowed the poly(NIPAm-b-BVIm[FcCOO])-rGO with thermal responsiveness, while the anion moiety provided additional electroactive function. It is noteworthy that the conformational change of PNIPAm segment upon different temperature could reveal or seal the redox probe of FcCOO-, thereby leading to a controllable expression of electroactivity switching by thermal stimuli. Owing to such regulation on surface property and conformation of PNIPAm segment, the modified electrode exhibited excellent thermally responsive electrocatalysis with reversible 'ON-OFF' effect toward the detection of ascorbic acid (AA), which led to two different catalytic states at the same electrode. The reversible electrocatalytic performance with switching capability of the poly(NIPAm-b-BVIm[FcCOO])-rGO/GCE is expected to have a broad application in the field of intelligent electrochemical sensors and devices.The lipidomic research is currently devoting considerable effort to the harmonization that should enable the generation of comparable and accurate quantitative lipidomic data across different laboratories and regardless of the mass spectrometry-based platform used. In the present study, we systematically investigate the effects of the experimental setup on quantitative lipidomics data obtained by two lipid class separation approaches, hydrophilic interaction liquid chromatography (HILIC) and ultrahigh-performance supercritical fluid chromatography (UHPSFC), coupled to two different quadrupole - time of flight (QTOF) mass spectrometers from the same vendor. This approach is applied for measurements of 268 human plasma samples of healthy volunteers and renal cell carcinoma patients resulting in four data sets. We investigate and visualize differences among these data sets by multivariate data analysis methods, such as principal component analysis (PCA), orthogonal partial least square discriminant analysis (OPLS-DA), box plots, and logarithmic correlations of molar concentrations of individual lipid species. see more The results indicate that even measurements in the same laboratory for the same samples using different analytical platforms may yield slight variations in the molar concentrations determined. The normalization to a reference sample with defined lipid concentrations can further diminish these small differences, resulting in highly homogenous molar concentrations of individual lipid species. This strategy indicates a potential approach towards the reporting of comparable quantitative results independent from the quantitative approach and mass spectrometer used, which is important for a wider acceptance of lipidomics data in various biomarker inter-laboratory studies and ring trials.
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