基于实时荧光聚合酶链式反应快速检测食源性大肠埃希氏菌O157:H7

目的 建立一种快速、灵敏、特异、高效的食源性大肠埃希氏菌O157:H7型实时荧光聚合酶链式反应(polymerase chain reaction, PCR)检测方法。方法 针对大肠埃希氏菌O157:H7型的O抗原特异基因rfbE保守区域设计特异性引物和探针, 合成基因片段绘制标准曲线, 在菌液基因组DNA和质粒双层面调试优化以完成方法的初步建立。其后, 对该方法的特异性、敏感性、重复性等进行全面的质量评估验证。结果 该方法特异性100%; 基因组DNA检测敏感性为7.11×102 fg/μL; 纯培养物水平检测敏感性为1.0×102 CFU/mL; 重复性变异系数在0.10%~1.00%之间; 标准曲线相关系数r2为0.9994。结论 成功建立了一种性能良好的大肠埃希氏菌O157:H7型实时荧光探针PCR快速检测方法, 该方法具有灵敏度高、特异性强、扩增时间短, 仅为35 min的特点, 可用于疑似大肠埃希氏菌O157:H7型污染样品的快速诊断检测。     

红毛藻R-藻红蛋白的高效制备以及抗体标记与检测

采用硫酸铵盐析和DEAE-Sepharose阴离子交换柱层析相结合,从红毛藻（Bangia fusco-purpurea）中分离纯化到纯度系数（A565/A280）大于6.0的R-藻红蛋白。SDS-PAGE结果显示,其亚基分子量分别为19、21ku。用适宜摩尔浓度的异型双功能交联剂N-琥珀酰亚氨基-3-2-吡啶基二硫丙酸醇（SPDP）将纯化的R-藻红蛋白与羊抗小鼠IgG抗体交联,利用SDS-PAGE和荧光检测鉴定R-藻红蛋白与抗体的交联效果。结果显示:R-藻红蛋白能与羊抗小鼠IgG成功交联。分别采用Dotblot和Westernblot对R-藻红蛋白标记的抗体作为二次抗体,小鼠抗鲢鱼主要过敏原小清蛋白单克隆抗体为一次抗体;对鱼类小清蛋白进行免疫检测,结果显示:R-藻红蛋白标记的抗体能检测相关抗原的存在,且有良好的特异性。利用藻红蛋白荧光探针可缩短免疫杂交的检测时间,简化操作过程。      

纤维素纳米晶荧光探针的制备及其对Fe3+荧光传感检测

将纤维素纳米晶(CNC)与N-(4-氨基苯基)-4-(N,N-二甲基乙二胺基)-1,8-萘酰亚胺(EADANI)进行共价键结合,制备得到纤维素纳米晶荧光探针(FCNC),并应用于Fe³⁺的荧光传感检测。结果表明,由于表面羧基和羟基的存在,FCNC具有较好的水分散性,在水溶液中呈现良好的黄色荧光发射性能;Fe³⁺对FCNC具有荧光增强效果,荧光增强因子达9.5,同时在竞争性离子存在情况下,FCNC表现出良好的选择性。     

一种Zn^2＋离子荧光探针的合成及其荧光性质

以2,3-二氨基甲苯为原料经过氨基保护、澳代、水解等反应制备2,3-二氨基苯甲醇,后者与芳香醛缩合成苯并咪唑,再经Mn02氧化、缩合生成2-（4-（4-（羟甲基）-1H-苯并[d]咪唑-2-基）-1H-苯并[d]咪唑-2-基）苯酚。经1^H—NMR对中间体和目标产物进行结构表征,并研究了产物的紫外、荧光性质,结果表明目标化合物能选择与Zn^2＋进行配位,产生较强的荧光,荧光量子收率为0．64,斯托克斯位移为142nm。     

Evaluation of intermodel agreement using ISO 13655 M0, M1, and M2 measurement modes in commercial spectrophotometers

Spectrophotometers are routinely used for color measurement and color management in many commercial printing and proofing workflows. In the case of media containing optical brightening agents, ultraviolet (UV)‐induced fluorescence has led to poor levels of agreement between models from different manufacturers, and different models from the same manufacturer. A relevant standard, ISO 13655, has been revised and now clearly defines measurement modes and conditions for the UV component in spectrophotometers. ISO 13655:2009—Graphic Technology—Spectral Measurement and Colorimetric Computation for Graphic Arts Images now defines four measurement modes: M0, M1, M2, and M3. The intermodel difference between 10 commercially available spectrophotometers is evaluated for different substrate types in measurement modes (M0, M1, and M2) as allowed by each instrument. In particular, the authors compare devices using M0 legacy mode versus newer instruments that are compliant with the new M1 and M2 (UV‐included and UV‐excluded) measurement modes. A finding with significant practical applications is that there is greatly improved intermodel agreement between the new generation of ISO 13655‐compliant instruments in M1 (D50) mode when compared with the previous generation of hand‐held spectrophotometers. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 27–37, 2017     

Layered Nanoprobe for Long‐Lasting Fluorescent Cell Label

A long‐lasting particle‐based fluorescent label is designed for extended cell imaging studies. This onion‐like nanoprobe is constructed through layer‐by‐layer fabrication technology. The nanoprobes are assembled with multiple layers of optically quenched polyelectrolytes, the fluorescence signal of which can be released later by intracellular proteolysis. Upon incubation with cells, the assembled nanoprobes are taken up efficiently. The tight packing and layered assembly of the quenched polyelectrolytes slow subsequent intracellular degradation, and then result in a prolonged intracellular fluorescence signal for up to 3 weeks with no noticeable toxicity.     

Up-converting NaYF4：0.1%Tm^3＋, 20%Yb^3＋ nanoparticles as luminescent labels for deep-tissue optical imaging

Optical imaging plays an important role in biomedical research being extremely useful for early detection, screening and image-guided therapy. Lanthanide-doped up-converting nanoparticles were ideally suited for bioimaging because they could be ex- cited in near infrared （NIR） and emit in NIR or visible （VIS）. Here, we compared lanthanide doped up-converting NaYF4 and organic fluorophores for application in deep-tissue imaging. For that purpose - tissue phantoms mimicking the natural properties of light scat- tering by living tissues were prepared. The studies allowed to quantitatively compare optical resolution of different fluorescent com- pounds, revealing that the NIR photoexcitation was favorable over conventional UV photoexcitation.     

一种新颖直管形节能荧光灯安全要求的检验方法探索

针对目前在市场上新出现的一种新颖直管形节能荧光灯，由于没有相应的国家或地方性产品质量标准，本文参照类似产品的国家标准提出了安全要求的检验项目和检验方法，并按提出的检验项目和检验方法对此类节能荧光灯进行了检验，实验结果表明，样品存在使用者可能触电的安全隐患，并分析了造成产品不合格的原因。     

A reliable and sensitive time-resolved fluorescent immunochromatographic assay (TRFICA) for ochratoxin A in agro-products

Immunochromatographic assays (ICAs) are considered as a suitable diagnostic tool for the detection of mycotoxins. Mycotoxins and especially, ochratoxin A are analytes with more demanding sensitivity requirements. To enhance the sensitivity of current immunochromatographic assays for ochratoxin A (OTA), a novel sensitive ICA was developed in this study. In the assay, microspheres enclosing fluorescent europium (III) [Eu(III)] nanoparticles (EuNPs) were used as a label for OTA monoclonal antibody (OTA-mAb) conjugation. Accordingly, assay was called time-resolved fluorescent immunochromatographic assay (TRFICA). The test strip was composed of three parts: a sample pad, nitrocellulose membrane and an absorbent pad. As for detection, a proper concentration of conjugated microspheres was pipetted into the microtube and sample extract was added to it. Then the strip was inserted into the tube and the fluid flow along the strip. The TRFICA results were obtained in 8 min and read by a portable TRFICA strip reader. The established method allows quantitative determination of OTA with limit of detection as low as 1.0 μg kg⁻¹ in the samples. For validation, spiked samples including wheat, maize, soybean and rice were respectively assayed by TRFICA and a standard high performance liquid chromatography equipped with a fluorescence detector (HPLC-FLD), and good agreement of results was obtained between two methods.     

化妆品中动物源性成分多重实时荧光PCR检测方法的研究

使用优化的Chelex-100结合玻璃奶法提取膏状、液态和固态化妆品中的动物源性DNA;根据驴、马和牛线粒体16S rRNA基因序列设计通用引物和特异性探针,建立了一次性检测化妆品中驴、马和牛3种动物源性成分的多重实时荧光PCR体系,检出限均为0.001 ng。并对市售的面霜、洗面奶和面膜进行盲样检测,验证了体系的可靠性和准确性。