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Interestingly, with the increment of pH from 5 to 10, the ratio of IFE in fluorescence quenching gradually decreases accompanied by an increment of FRET ratio, resulting in the high sensitivity and responsivity for detecting p-nitrophenol at a wide range of pH. Clearly, the MoS2 NQD-based sensing approach demonstrates a promising potential for selective detection and fast analysis of pollutants in environment monitoring and security screening.Dipicolinic acid (DPA) is a unique biomarker of Bacillus anthracis. Development of a simple, fast, sensitive and timely DPA detection method is of great importance and interest for preventing mass disease outbreaks and treatment of anthrax. In this work, a novel lanthanide-doped fluorescence probe was constructed by coordination of Eu3+ with bifunctional UiO-66-(COOH)2-NH2 MOFs materials for efficient monitoring DPA. UiO-66-(COOH)2-NH2 MOFs were prepared using Zr4+ as a metal node, 1,2,4,5-benzenetetracarboxylic acid (H4BTC) and 2-aminoterephthalic acid (NH2-BDC) as bridging ligand through a simple one-pot synthesis method. By virtue their abundant carboxyl groups, UiO-66-(COOH)2-NH2 can readily grasp Eu3+ to form UiO-66-(COOH)2-NH2/Eu with coordinated water molecules at Eu sites. Upon interaction with DPA molecules, the coordinated H2O molecules were replaced by DPA molecules which transfer energy to Eu3+ in UiO-66-(COOH)2-NH2/Eu and sensitize Eu3+ luminescence. Meanwhile, DPA has a characteristic absorption band at 270 nm, which overlapped with the excitation spectrum of NH2-BDC, allowing the fluorescence of UiO-66-(COOH)2-NH2/Eu at 453 nm to be greatly quenched by DPA through inner filter effect (IFE). Therefore, the rationally designed UiO-66-(COOH)2-NH2/Eu complex not only exhibits strong hydrophilicity and high dispersion, but also serves as ratiometric fluorescence sensing platform for monitoring DPA concentration. This sensing platform showed a satisfactory linear relationship from 0.2 μM to 40 μM with a limit of detection of 25.0 nM and a noticeable fluorescence color change from blue to red, holding a great promise in practical applications.Fluphenazine HCl (FLU) is an anxiolytic, while Nortriptyline HCl (NOR) is an anti-depressant. They are co-formulated together to treat depression and schizophrenia. Perphenazine (PER) and dibenzosuberone (DBZ) are the pharmacopeial impurities of FLU and NOR, respectively. Four spectrophotometric and multivariate chemometric methods were developed to determine the two drugs together or in presence of their two impurities in their bulk and pharmaceutical formulation. Method (A) is the triple divisor-ratio derivative (TDR) method, where the zero order spectrum of each component was divided by a mixture of the other 3 components, then the peak amplitudes of the first derivative spectra of FLU, NOR and DBZ were measured at 265, 245.4 and 283.2 nm, respectively. Method (B) is the double divisor-ratio difference-dual wavelength (DD-RD-DW) method, in which each component spectrum mixture was divided by a binary mixture of 2 of the interfering components. In the resulting ratio spectra, the amplitude difference is calculated between 2 wavelengths at which the third interfering component has zero difference. Methods (C and D) are the principle component analysis (PCA) and partial least squares (PLS) models. Methods (A and B) failed to quantify PER (FLU impurity), while (C and D) succeeded to quantify all components. The four methods have been applied for the prediction of the FLU and NOR in their pharmaceutical formulation with good accuracy and precision. The proposed methods have been validated according to the ICH guidelines and the results were within the acceptable limits.Community drug checking provides an essential service that responds to the unpredictable and variable supply of illicit drugs. Point of care detection of trace components using portable infrared spectrometers is a harm reduction measure to prevent overdose. This study investigates the ability of weighted subtraction and two-trace two-dimensional (2T2D) correlation analysis to reveal the presence of heroin in an opioid mixture that contains heroin and fentanyl mixed with caffeine as a cutting agent. In both methods, a spectral trace was identified that provided reasonably high correlation scores to heroin when compared to entries in drug libraries. The two-trace correlation analysis produced a higher match score, suggesting that future improvements in spectral unmixing methods may enhance the reliability of detecting trace components in drugs.Metal nitrogen-doped carbon (MNC) nanozymes have received increasing attention in bio-catalysis filed due to adequate catalytic activity, outstanding stability and reusability. Herein, the Fe/NC nanozymes (Fe/NC NZs) with peroxidase-like activity was successfully synthesized and a fluorescence turn on and colorimetric dual-mode sensing system was developed for quantification of captopril (CP) based on Fe/NC NZs and orange-emitting carbon dots (O-CDs). The Fe/NC NZs as an enzyme mimic can efficiently catalyze the 3,3',5,5'-tetramethylbenzidine (TMB) chromogenic reaction, forming blue-colored oxidized TMB product (oxTMB) with the presence of H2O2, leading to the fluorescence quenching of O-CDs simultaneously via the inner filter effect (IFE). When CP was present, the blue oxTMB was reduced to colorless TMB, resulting in the inhibition of IFE and the recovery of fluorescence of O-CDs. The fluorescence increase of O-CDs and absorbance decrease of oxTMB depended on CP concentration. Good linear relationships of fluorescence and colorimetric sensing towards CP were obtained in the range from 1 to 50 μM, and the detection limits were 0.47 and 0.56 μM, respectively. Moreover, this as-constructed dual-mode sensor was used to detect CP in pharmaceutical products with satisfactory results.Surface enhanced Raman spectroscopy (SERS) is a promising technique for trace determination. More and more attention is focused on hybrid SERS substrates, which coupled with noble metal nanoparticles and carbon-based materials. Herein, expanded graphite (EG) is used to prepare EG-covered support by ultrasonic washing and filtration. Such support is flexible and can be cut into any shape. And the contact angle (θe) for Au nanorods (Au NRs) sol on the EG-covered support was 108.2° and the hydrophobic surface is helpful for Au NRs to construct 'hot spots' during evaporation. The limits of detection (LOD) for crystal violet (CV), thiram, malachite green (MG) and methylene blue (MB) were as low as 1 ppb, 50 ppb, 1 ppb and 1 ppb, respectively. Moreover, a fast and convenient 'paste-sampling' method could be employed for trace contaminants on real samples, because EG-based Au NRs substrate is of flexibility and porosity. Thus, CV residue on shrimp could be determined lower than 1 ppb and thiram residue on grapes could be identified lower than 50 ppb. In addition to high sensitivity, the stability of EG-based Au NRs substrate is also very good. Even after acid/alkali pretreatment (pH = 4∼10) or 30 min of thermal treatment (T = 20∼100 °C), the enhancement of the substrate remained stable. What's more, the substrate could be stored as long as 30 days. The highly stable, sensitive, cost-effective and easy-to-produce EG-based Au NRs substrates exhibit a great potential to promote application of SERS for routine analysis.Belamcandae Rhizoma is a widely used traditional Chinese herbal medicine with isoflavones as the main active ingredient. In this paper, an integrated strategy was developed to discover and identify new isoflavones in Belamcandae Rhizoma by an ultra-high-performance liquid chromatography coupled with high resolution multistage mass spectrometry. Different characterization methods were used based on structural features of isoflavone aglycones and glycosides. On one hand, we adopted a data-dependent acquisition mode incorporated into intelligent AcquireX deep scan algorithms to analyze crude extract, and used a mass defect filtering technique to filter out two kinds of isoflavone aglycones from the extract. On the other hand, neutral-loss-triggered MSn was used to analyze isoflavone glycosides, and under this acquisition mode, MSn scan only took place when chemical components exhibited specific neutral losses. Identification of isoflavones was achieved either by comparison with reference compounds or analysis of characteristic product ions based on MS2 or MSn fragmentation patterns. UV absorbance spectra also contributed to the confirmation of isoflavones. As a result, a total of 65 isoflavone aglycones (42 new aglycones) and 142 isoflavone glycosides (122 new glycosides) were discovered, including a number of trace components. Meanwhile, modifications of new sugar moieties, such as xylose, rhamnose and 6-O-(4‑hydroxy-3,5-dimethoxybenzoyl)-β-D-glucose, were discovered in Belamcandae Rhizoma for the first time. These results indicated the feasibility of this established strategy for in-depth identification of new isoflavone aglycones and glycosides.Traditional Western blots are commonly used to separate and assay proteins; however, they have limitations including a long, cumbersome process and large sample requirements. Here, we describe a system for Western blotting where capillary gel electrophoresis is used to separate sodium dodecyl sulfate-protein complexes. The capillary outlet is threaded into a piezoelectric inkjetting head that deposits the separated proteins in a quasi-continuous stream of less then 100 pL droplets onto a moving membrane. click here Through separations at 400 V/cm and protein capture on a membrane moving at 2 mm/min, we are able to detect actin with a limit of detection at 8 pM, or an estimated 5 fg injected. Separation and membrane capture of sample containing 10 proteins ranging in molecular weights from 11 - 250 kDa was achieved in 15 min. The system was demonstrated with Western blots for actin, β-tubulin, ERK1/2, and STAT3 in human A431 epidermoid carcinoma cell lysate.Three magnetic covalent organic frameworks (named M-TpPa-SO3Na, M-TpPa-SO3H and M-TpPa) were prepared by the solvothermal synthesis method with 1,3,5-trimethylphenol (TP) and either 2-sulfo-1,4-phenylenediamine (Pa-SO3H) or p-phenylenediamine (Pa) as monomers. Among them, the M-TpPa-SO3Na possessed relatively high hydrophilicity, good magnetic responsiveness, and high affinity for the benzoylureas (BUs) insecticides. It was then explored as the magnetic solid-phase extraction adsorbent for the extraction of six BUs (diflubenzuron, triflumuron, hexaflumuron, teflubenzuron, flufenoxuron and chlorfluazuron) from water, pear juice and honey samples prior to high-performance liquid chromatography with ultraviolet detection. Under the optimized experimental conditions, a good linearity was achieved within the concentration range of 0.27-40.0 ng mL-1 for water sample, 0.47-30.0 ng mL-1 for pear juice sample, and 2.70-200.0 ng g-1 for honey sample. The limits of detection for the analytes were 0.08-0.11 ng mL-1 for water sample, 0.14-0.19 ng mL-1 for pear juice sample and 0.80-1.00 ng g-1 for honey sample. The method recoveries for spiked samples were in the range of 85.0%-111.0% with the relative standard deviations less than 8.8%. The developed method was successfully used for the determination of the BUs in water, pear juice and honey samples.