Filter-based surface-enhanced Raman spectroscopy for rapid and sensitive detection of the fungicide ferbam in water

Surface-enhanced Raman spectroscopy (SERS) has been widely applied for rapid and sensitive detection of various chemical and biological targets. Here, we incorporated a filter syringe system into the SERS method to detect the fungicide ferbam in water. Silver nanoparticles (Ag NPs) were aggregated by sodium chloride (NaCl) to form nanoclusters that could be trapped in the pores of the filter membrane to from the SERS-active membrane. Then samples were filtered through the membrane. After capturing the target, the membrane was taken out and air dried before measuring by a Raman instrument. After optimisation of various parameters, the developed filter SERS method was able to detect the fungicide ferbam as low as 2.5 μg/L and had a good quantitative capability. The developed method was successfully applied in three water samples, including double-distilled water, tap water, and pond water. The test can be carried out on site using a portable Raman instrument. This study shows that the filter-based SERS method improves the detection capability in water samples, including the sensitivity and portability, and could be applied in the detection of various toxins in real-world water samples.     

Structural modification of BODIPY: Improve its applicability

The synthesis of biocompatibility and tissue penetrating BODIPY dyes have been summarized.     

Microstructure and anti‐ wear and corrosion performances of novel UHMWPE/graphene‐nanosheet composite coatings deposited by flame spraying

Ultra‐high molecular weight polyethylene (UHMWPE)/graphene‐nanosheet (GN, multiple layers of graphene sheets with the thickness of ~5–10 nm) coatings have been deposited by flame spraying. The structure of UHMWPE remained almost intact after the spray processing and addition of GNs resulted in a slightly decreased crystallinity and improved thermal stability of UHMWPE. In addition, the coating containing 1.0 wt.% GNs exhibited a reduction of ~20% in wear rate and 25% in friction coefficient (0.18 versus 0.24). Significantly enhanced anti‐corrosion performances of the UHMWPE–GN coatings were suggested by increased corrosion potential, corrosion current density, and impedance modulus value of the UHMWPE–GN coatings. The very well retained GNs are located mainly at the interfaces between UHMWPE splats and act as bridges connecting the splats, which mainly accounts for the enhanced properties of the composite coatings. The novel UHMWPE–graphene composite coatings show great potential for protecting engineering components for applications against corrosion. Copyright © 2013 John Wiley & Sons, Ltd.     

Development of a filtration-based SERS mapping platform for specific screening of Salmonella enterica serovar Enteritidis

The presence of Salmonella in natural freshwater and drinking water is a leading cause of intestinal illness all over the world; thus, the detection of Salmonella in water is of great importance to public health. The objective of this study is to develop a rapid screening method for the detection of Salmonella enterica serovar Enteritidis in water involving surface-enhanced Raman spectroscopy (SERS), aptamers, and filtration. SERS offers a great alternative to traditional methods of pathogen detection, with a simplified detection assay and shortened detection time. The specific capturing and labeling of Salmonella Enteritidis are realized by a specific single-stranded DNA aptamer, which is modified with an additional chain of adenine and fluorescein (FAM) and used as presence/absence indicator of Salmonella Enteritidis. By incorporating a vacuum filtration system, bacterial cells recognized by the specific aptamer are concentrated onto a membrane. With additional filtration of gold nanoparticles, the aptamer signals were captured and used to construct a SERS mapping indicating the presence and absence of target bacterial strains with potential quantitative capability. The specificity of the method was validated by using other strains of bacteria such as Escherichia coli and Listeria monocytogenes. The sensitivity of the method goes down to 10³ CFU/mL for 1 mL of sample with a total detection and analyzing time within 3 h. This study demonstrates the capability of the filtration-based SERS platform for detecting Salmonella Enteritidis in various aqueous matrices such as distilled water and rinsing water from fresh produce with high selectivity and sensitivity.

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High Expression Level of α2-3-Linked Sialic Acids on Salivary Glycoproteins of Breastfeeding Women May Help to Protect Them from Avian Influenza Virus Infection

Terminal sialic acids (Sia) on soluble glycoprotein of saliva play an important role in the clearance of influenza virus. The aim of this study is to investigate the alteration of sialylation on the salivary proteins of women during the lactation period and its effect on the saliva binding ability to virus. In total, 210 saliva samples from postpartum women with and without breastfeeding were collected, and the expression level of α2-3/6-linked Sia on the whole salivary proteins and specific glycoproteins of IgA and MUC5B from different groups were tested and verified using lectin microarray, blotting analysis and ELISA based method. The H1N1 vaccine and three strains of Avian influenza virus (AIV) were used for the saliva binding assay. Results showed that the variation in salivary expression level of α2-3-linked Sia was much more obvious than the α2-6-linked Sia, which was up-regulated significantly in the breastfeeding groups compared to the non-breastfeeding groups at the same postpartum stage. Furthermore, the binding abilities of salivary glycoproteins to AIV strains and H1N1 vaccine were increased in breastfeeding groups accordingly. This finding adds new evidence for the maternal benefit of breastfeeding and provides new thinking to protect postpartum women from AIV infection.     

Breathing Micelles for Combinatorial Treatment of Rheumatoid Arthritis

Breathing process involves inhalation and exhalation of different gases in animals. The gas exchange of the breathing process plays a critical role in maintaining the physiological functions of living organisms. Although artificial breathing materials exhibiting volume expansion and contraction upon alternate exposure to different gases have been well explored, those being able to realize the gas exchange remain elusive. Herein, we report breathing micelles (BM) capable of inhaling nitric oxide (NO) and exhaling carbon monoxide (CO), both of which are endogenous gaseous signaling molecules. We demonstrate that BM can simultaneously scavenge overproduced NO and attenuate proinflammatory cytokines in lipopolysaccharide (LPS)-challenged macrophage cells. In vivo studies revealed that BM outperformed conventional nonsteroidal anti-inflammatory drugs such as dexamethasone (Dexa) in treatment of rheumatoid arthritis (RA) in adjuvant-induced arthritis (AIA) rats, likely due to the combinatorial effect of NO depletion, CO-mediated deactivation of inducible NO synthase (iNOS) and activation of heme oxygenase-1 (HO-1). This work provides new insights into artificial BM for potential biomedical applications.     

Synthesis and application of highly sensitive fluorescent probe for Hg2+ regulated by sulfur

Rhodamine-based fluorescent probe is widely used in chemical analysis, environmental analysis and life sciences area due to their excellent optical properties. Based on the thiophilic property of Hg~(2+), using C = S structural motif as the core segment, our group have designed and synthesized three novel probes containing cinnamyl aldehyde with different substituents, exhibiting high selectivity and excellent sensitivity. The structure-property relationships of these probes have been investigated that the optical change caused by electron withdrawing effect and heavy atom effect. Furthermore, these Hg~(2+) probes could be applied in living mice imaging, which provide a promising tool for quantitative mercury(Ⅱ) ion imaging in living organism.     

应用超临界流体萃取分离-气相色谱-质谱分析法建立中药温郁金的指纹图谱及其系统聚类分析

收集生长于浙江省瑞安市8个产地的温郁金样品14批次,分别经清洗、冷冻干燥及碾磨粉碎,得到通过0.425mm筛孔药筛的粉末状样品14个。称取此样品各30g,分别按试验选定的最佳条件[萃取温度35℃,萃取压力15MPa,萃取时间(静态30min,动态90min)]进行超临界流体萃取分离,所得萃取物收集于甲醇5mL中,并进行气相色谱-质谱法(GC-MS)分析。色谱分离采用HP-5ms石英毛细管色谱柱和在50~220℃之间程序升温模式;质谱测定采用电子轰击离子源(EI),在质荷比(m/z)50~650内进行扫描。所得总离子流色谱图中共有50多个色谱峰,选择保留时间在40min以内的共有峰26个作为考察对象,选择保留时间为17.12min的莪术二酮为参考峰,计算共有峰的相对保留时间α和峰面积百分比S以及各样品与S3的S值的最大差值ΔS(Max)%,并建立了14个样品的指纹图谱。根据GC-MS分析所得结果并与NIST 14谱库比对,对共有峰作出鉴定。通过SPSS 16.0软件,采用系统聚类分析法对所分析的14批次温郁金样品的指纹图谱进行分类比较。应用指纹图谱对2个市售温郁金产品作了组分鉴定和产地认定。     

Qualitative and quantitative studies on chemical constituents of Ling-gui-zhu-gan decoction: In vitro and in vivo

Ling-gui-zhu-gan decoction has significant therapeutic effects in the treatment of diseases related to phlegm and fluid retention. In this study, we aimed to qualitatively characterize the chemical constituents of Ling-gui-zhu-gan decoction in vitro and in vivo by HPLC coupled to Fourier transform ion cyclotron resonance MS, and quantitively determine the contents of typical chemical constituents by HPLC method. As a result, a total of 75 chemical constituents were discovered including 37 flavonoids and their glycosides, 20 saponins, 9 sterols, 3 organic acids and their derivatives, 3 lactones, 2 coumarins, and 1 alcohol. Among them, 17 chemical constituents were specifically identified. Subsequently, an HPLC method was established for simultaneous determination of seven chemical constituents. Finally, a total of 40 prototype components were initially detected by HPLC-MS method in the biological samples of rats after their water extract was orally administrated. Among them, 29, 27, 12, and 32 prototype components were detected in plasma, bile, urine, and feces, respectively. Moreover, 34 metabolites, including 16 phase II metabolites, were detected for the first time. In conclusion, this study lays the foundation for the identification of chemical components in vitro and in vivo and the elucidation of the potential pharmacodynamic components of Ling-gui-zhu-gan decoction.