07 μM) among all reported materials to citric acid (CA) to date. This work opens up new application prospects in colorimetric sensing system for food quality control and safety, biotechnology and clinical diagnosis.Appropriate prescription of antibiotics requires the pharmacokinetic knowledge of the drugs and their metabolites in blood, and their distribution/retention in organ tissues. Here we report that highly crystalline graphite dots (GDs) allow for quantitative profiling of antibiotic metabolites in a spatial-temporal manner, in combination with matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI MSI). GDs matrix features an ultra-clean background base line and high efficiency in ionization of small molecules, thus enabling quantification of sulfamethoxazole (SMZ) and its metabolites with limit of detection (LOD) in the femtomole range. Distinctly different from the other MS techniques, our approach is tolerant to high levels of salt contaminants in the complexed biological samples, thus minimizing the sample purification requirements and allowing for tests in small volumes. We have demonstrated quantitative measurements of the dynamic concentration changes of SMZ (m/z 276.27) and two metabolites, N4-hydroxy-SMZ (m/z 292.28) and N4-acetyl-SMZ (m/z 318.31) with only 1 μL mouse blood sample for each test. High-resolution distribution patterns of SMZ metabolites have directly been visualized a on the liver subsegments. Therefore, it allows for simultaneously acquisition of pharmacokinetic data in the blood combined with detailed hepatic zonation of SMZ metabolites for the first time. As a rapid, high-throughput platform to monitor small molecules in vivo, our approach of GDs-assisted MADLI MSI will foster the medical research on the antibiotic usage and drug development.A new method for fishing antitumor ingredients by G-quadruplex recognition from Macleaya cordata seeds extracts was established using a three-phase-laminar-flow-chip (TPL chip). The TPL chip integrated the separation of drugs from the complex ingredients and organic solvent extraction, simplifying pretreatment processes and reducing reagents and time. In addition, the chip method showed a lower false negative result, owing to the gentle membrane-free filtration process based on diffusion separation in microchannel. Four ligands with high content in alkaloids of Macleaya cordata seeds were selected, those are chelerythrine (CHE), sanguinarine (SAN), protopine (PRO), and allocryptopine (ALL), which demonstrated affinity with G-quadruplex and were potential for antitumor.Novel magnetic molecularly imprinted nanobeads for 17β-estradiol (E2), namely, E2-MMINs, were synthesized by molecularly imprinted polymers on the surface of magnetic nanobeads in aqueous solvents. The hydrophilic nanobeads were set up by adopting carboxyl group-functionalized Fe3O4 nanoparticles as carriers, E2 as template molecule, and dopamine as functional monomer. The synthesized E2-MMINs were investigated in different aspects including synthesis conditions, physical and chemical properties, and adsorption conditions. The experimental results show that the E2-MMINs present not only thin imprinting layers, stable crystal form, and fast magnetic separation ability, but also rapid kinetics (20 min), high binding amount (41.48 mg g-1), satisfactory specificity (imprinting factor = 8.07), and favorable reusability (adsorption efficiency > 94.8% after reusing for 10 times). Moreover, the method employing E2-MMINs combined with high performance liquid chromatography for the specific enrichment and determination of trace E2 has been developed with the low LOD (0.008 μg L-1), and the application in environmental water samples has been proved. This work demonstrates that the proposed synthetic strategy is highly promising to the synthesis of hydrophilic nanobeads for efficient enrichment and detection of target molecule E2.Halloysite nanotubes loaded with 4-aminothiophenol capped silver nanoparticles (mHNTs-AgNPs4-ATP) composite was synthesized as a sensitive surface-enhanced Raman scattering (SERS) probe for the determination of nitrite ions in sausage and pork luncheon meat. The as-prepared composite was characterized by transmission electron microscope, X-ray diffraction spectroscopy and Fourier transform infrared spectroscopy. The as-synthesized mHNTs-AgNPs4-ATP composite with evenly distribution of AgNPs can provide in-situ derivatization site for sensitive and selective SERS detection of nitrite ions. Under acid condition, the 4-ATP capped on the AgNPs can be transformed into p,p'-dimercaptoazobenzene (DMAB) through nitrite-triggered diazo reaction. This efficient nitrite-triggered reaction can be used to detect nitrite via the characteristic peaks of DMAB at 1143 cm-1, 1392 cm-1, and 1434 cm-1. This SERS method has a wide logarithmic range of 0.0069-6.9 mg L-1, with detection limit of 0.78, 3.4, 0.51 μg L-1 at the peak of 1143 cm-1, 1392 cm-1, and 1434 cm-1, respectively. Besides, this method can be applied to detect nitrite ions in sausage and pork luncheon meat with relative standard deviation less than 10.3%, and the results were consistent with that analyzed by UV-Vis method. This method has good potential in efficient detection of meat product in food safety.Fluorescence detection technology has been widely concerned for its advantages of low cost, simple operation, good sensitivity, real-time and non-destructive biological imaging. However, most fluorophores emit bright fluorescence in solution, and the fluorescence decreases significantly in the high concentration or solid/aggregated state, which is called aggregation-caused quenching (ACQ). Cysteine (Cys) is an important kind of amino-acid in the field of bio-medicine, whose main function is to participate in metabolism and protein synthesis, detoxification, but intracellular cysteine concentrations (30-200 μM) are much low, and direct detection of endogenous cysteine is hampered by interference with other thiols. https://www.selleckchem.com/products/idasanutlin-rg-7388.html To solve the above problems, based on solid-state fluorophore HPQ, we for the first time prepared a novel solid-state fluorescence probe MA-HPQ, for monitoring of endogenous Cys, operated by the mechanism of excited intramolecular proton transfer (ESIPT). MeO-HPQ is completely insoluble in water, has very strong solid-state fluorescence with the maximum emission wavelength of 510 nm and the maximum excitation wavelength of 365 nm.