ß-cyclodextrin-modulated ratiometric supramolecular BODIPY fluoroprobe for highly selective and sensitive detection of thiophenol.

Thiophenol (PhSH) is an important industrial intermediate but displays significant toxicity towards environmental and biological systems. Here, we introduce a supramolecular system based on ß-cyclodextrin (ß-CD) and boron dipyrromethene (BODIPY) as a ratiometric fluorescence probe to discriminate PhSH in environmental water samples, cells, and in vivo. In aqueous solutions, BODIPY shows extremely weak fluorescence intensity due to its aggregation into nanometer-sized clusters, which prevents its interaction with thiols. However, within a ß-CD environment, it can selectively and sensitively detect PhSH. Also, the stability of the probe was significantly improved. The mechanism studies based on stoichiometry, NMR spectroscopy, and theoretical calculation revealed distinct intermolecular interactions between ß-CD and BODIPY, including host-guest interactions and hydrogen bonds. Low limit of detection (10.7 nM) and rapid response time (5 min) have been achieved, and the practicality of the supramolecular system (BODIPY@ß-CD) has been verified by actual sample analysis. Furthermore, the first hydrogel-based sensing system for portable PhSH detection has been developed, facilitating rapid and on-site colorimetric visualization across both liquid and gas phases. Most importantly, using a low amount of the probe, early stages of low-dose exposure to PhSH can be visualized in living cells and zebrafish. Therefore, BODIPY@ß-CD is a robust new monitoring tool for the detection of PhSH in various scenarios, indicating the promising application value of the host-guest supramolecular probe in detecting highly toxic substances.

Simple, fast and eco-friendly micro-solid phase extraction based on thiol and ionic liquid bi-functional nanofibers membrane for the determination of sulfonamides in environmental water.

BACKGROUND: Sulfonamides (SAs) are a class of synthetic antibacterial agents that are diffusely used in the medical industry and animal husbandry. Their prevalence in the influents and effluents of water treatment plants, as well as in rivers and groundwater, has provoked worldwide concern. Monitoring SAs in environmental water is of great significance for public health. However, most of the available detection techniques for SAs are cumbersome and time-consuming. With the increasing number of actual samples, simple, fast and environmentally friendly analytical methods are always in demand. RESULTS: Herein, we describe a highly efficient micro-solid phase extraction (µ-SPE) sample preparation technique based on a novel thiol and ionic liquid bi-functional nanofibers membrane (IL-SH-PAN NFsM) for multi-residue detection of sulfonamides (SAs) in water samples. By the synergistic effect of -SH and -IL, the as-prepared IL-SH-PAN NFsM demonstrated high adsorption capacity and excellent selectivity for SAs. The water samples can be directly used for µ-SPE without pH and ionic strength adjustment, and the eluent can be directly collected for HPLC-MS/MS analysis. Compared with other methods reported in the literature, this method required much shorter extraction time (2 min for a batch), much less amount of adsorbent (4.0 mg) and organic solvent (0.5 mL), while providing much higher sensitivity (1.4-3.9 ng L-1), and fine recoveries (88.8%-117.7%) with relative standard deviations less than 4.26%. SIGNIFICANCE AND NOVELTY: A bi-functional nanofibers membrane was prepared for efficient extraction of SAs. The adsorbent exhibited superior adsorption performance and excellent selectivity. The underlying interaction mechanisms derived from -SH and -IL were proposed, which provide a new idea for preparing versatile adsorbents. Rapid, efficient and sensitive detection of SAs in water was achieved. The novel sample preparation technique can be expected as an efficient method for routine trace SAs residue monitoring in various water samples.

Simple and efficient solid phase extraction based on molecularly imprinted resorcinol-formaldehyde resin nanofibers for determination of trace sulfonamides in animal-origin foods.

Novel molecularly imprinted resorcinol-formaldehyde resin nanofibers (MIRF NFs) was prepared using polydopamine as an intermediate. With high specific surface area and favorable usability, MIRF NFs presented high efficiency for the solid phase extraction (SPE) of sulfonamides (SAs) in complex animal foods. After optimizing the operating conditions, a new method for SAs quantification coupled with HPLC-MS/MS was developed. By simple water dilution of the solvent extracts, SPE could be carried out. In addition, the eluent could be analyzed directly without any further treatment. The newly developed method was simplified greatly with much fewer sample pretreatment procedures (4 steps). Moreover, much fewer amounts of sample (1.0 g), adsorbent (3.0 mg), organic solvent (1.5 mL) and preparation time (20 min for 24 samples) were needed. The obtained good linearity (R2 > 0.9957), low detection limits (0.01-0.14 µg kg-1), satisfactory recoveries (83.0 %-112.9 %) and precisions (RSDs < 12.6 %) further proved the feasibility of the method in practical application.

Effects of bFGF and alpha-MSH on adhesion and migration of human melanocytes in vitro / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To observe the effect of basic fibroblast growth factor (bFGF) and alpha-melanocyte stimulating hormone (alpha-MSH) on adhesion and migration of melanocytes in vitro.</p><p><b>METHODS</b>Human melanocytes were obtained from normal human foreskins. Culture dishes covered with fibronectin were used to perform melanocytes adhesion assay, and cell motility was assessed using the Transwell micropore filter method.</p><p><b>RESULT</b>bFGF and alpha-MSH increased melanocytes adhesion on culture dishes covered with fibronectin. bFGF stimulated melanocytes migration through micropore filter while alpha-MSH had no significant effects.</p><p><b>CONCLUSION</b>bFGF and alpha-MSH could promote the adhesion and migration of melanocytes, which suggests that two agents may play a role in the repigmentation of vitiligo.</p>