丹贝大豆甙元薄层层析测定

本文研究了丹贝中主要生物活性物质大豆甙元含量的薄层层析测定方法。最佳展开剂为甲醇：氯仿（１１：８９），大豆甙元的Ｒｆ值为０．６４．薄层层析扫描参数λＲ为２５０ｎｍ，λｓ＝３６０ｎｍ。大豆甙元在薄层板上１２ｈ内稳定，在０～０．３９３７ｍＭｏｌ／Ｌ范围符合比尔定律，回收率９８～１０２％、丹贝中大豆甙元含量为３７２．０×１０（－６）±１７．８×１０（－６）。     

辣根过氧化物酶酶学特性及应用进展

辣根过氧化物酶（HRP）是一种以亚铁血红素为氧化还原中心的过氧化物酶,从植物辣根的根部提取,目前被广泛地应用在污水处理、食品工业、有机合成和分析检测等领域。本文综述了辣根过氧化物酶的结构、固定化及辣根过氧化物酶在各个领域的应用,并对其工业应用前景及未来研究方向进行了探讨。     

固定化辣根过氧化物酶电化学测定有机过氧化物和亚硝酸盐

利用海藻酸钠（SA）水凝胶将辣根过氧化物酶（HRP）固定在玻碳电极表面,制备了HRP-SA膜修饰电极．包埋在海藻酸钠水凝胶中的辣根过氧化物酶可以与电极直接传递电子．在pH=7．0的磷酸盐缓冲溶液和磷酸盐,乙醇混合溶液中均可得到一对辣根过氧化物酶辅基血红素Fe（Ⅲ）／Fe（Ⅱ）电对的可逆氧化还原峰．研究了HRP-SA膜修饰电极对有机过氧化物（过氧化氢、氢过氧化叔丁基、氢过氧化异丙基苯、过氧化丁酮）和亚硝酸盐的电催化性质,表明该方法可用于上述物质的定量测定．     

速率法测定辣根过氧化物酶

本文介绍了一种速率法测定辣根过氧化物酶的方法。以对苯二胺和过氧化氢为底物经辣根过氧化物酶作用生成紫红色化合物.用440nm 单色光进行光电比色,每隔30秒钟记录一次吸光度值,直至3分钟为止。绘出吸光度时间关系曲线。求出斜率后,从标准工作曲线中查得样品中辣根过氧化物酶的含量。该方法可用于竦根过氧化物酶制备过程中每一操作步骤中酶的比活性测定。本法也可用于其他过氧化物酶的测定。     

三种辣根过氧化物酶标记羊抗人IgG方法的比较

目的 :探讨三种辣根过氧化物酶 (HRP)标记羊抗人IgG方法的差异。 方法 :应用过碘酸钠氧化法、简易戊二醛二步法和戊二醛 -过碘酸钠法三种HRP标记羊抗人IgG方法的酶标记物含量和浓度作了比较 ,同时对 4 5人份血清O .D值进行了比较。结果 :应用过碘酸钠氧化法的标记率 (LR)和克分子比均较简易戊二醛二步法、戊二醛 -过碘酸钠法高 ;且应用过碘酸钠氧化法制备的酶标记物效价远远高于其它两种方法。结论 :应用HRF标记羊抗人IgG制备酶标记物最好应用过碘酸钠氧化法     

大豆甙元对家兔回肠张力影响的分析

实验采用成都泰盟BL-生物机能实验系统，记录了家兔离体回肠张力。首先滴加大豆甙元进行观察。并分别用M型受体轱抗剂、α，β受体拮抗剂以及阿片受体阻断剂对家兔离体回肠张力活动中的相互作用进行观察，结果表明：大豆甙元对家兔离体回肠张力的频率、峰峰值均有抑制作用，分别滴加M型受体拮抗剂、α，β受体拮抗剂，以及阿片受体阻断剂均不影响大豆甙元的作用。     

辣根过氧化物酶在双十六烷基磷酸膜中的直接电化学

利用表面活性剂双十六烷基磷酸（DHP）将辣根过氧化物酶（HRP）固定在EPG电极表面,研究了酶中Fe(（Ⅲ）／Fe（Ⅱ）电对与电极之间的直接电子传递过程以及酶催化双氧水还原过程,结果表明：（1）表面活性剂是一种固定酶的理想材料;（2）这种体系可能应用于构造第三代生物传感器．     

自组装膜技术构筑双氧水的电化学酶传感器

利用自组装膜技术构筑H2O2的电化学生物传感器，以共价键合在电板表面的NB为媒介体，辣根过氧化物酶为生物敏感组分，具有灵敏度高、稳定性好、抗干扰能力强的特点。     

辣根过氧化物酶催化合成壳聚糖-没食子酸甲酯的条件研究

以辣根过氧化物酶（HRP）为催化剂,催化合成壳聚糖-没食子酸甲酯。探讨了接枝条件（酶用量、壳聚糖与底物浓度比例、底物浓度、反应时间等）对接枝率的影响,通过FTIR对其产物进行结构表征。结果表明,酶法催化合成适宜条件：辣根过氧化物酶（酶活力为40U/mL）用量为0.7mL,壳聚糖与没食子酸甲酯的量浓度比为3∶1,没食子酸甲酯浓度为7mmoL/L,反应时间2h。用线性电位滴定法测其接枝率为11.0%～37.2%。     

溶胶-凝胶杂化膜固定介体和酶的过氧化氢、葡萄糖生物传感器

以通过溶胶-凝胶技术制备的SiO2/Nafion杂化膜固定辣根过氧化物酶,以杂化膜中的Nafion固定的亚甲基蓝为辣根过氧化物酶和玻碳电极间的电子传递介体,制成了电流型单酶过氧化氢生物传感器。在此基础上通过固定双酶（辣根过氧化物酶-葡萄糖氧化酶）制成了葡萄糖生物传感器。探讨了杂化膜的制备条件、生物传感器的性能和工作电位、pH值、温度、干扰物质等对生物传感器的影响。单酶生物传感器线性响应范围为1.0×10-6～1.6×10-4mol/L,检测限为6.0×10-7mol/L（S/N=3）,达到95%稳态响应电流用时少于15s。双酶葡萄糖生物传感器线性响应范围为7.8×10-6～2.4×10-3mol/L。检测限为4.2×10-6mol/L（S/N=3）,达到95%稳态响应电流用时少于25s。     

Development of a class-specific polyclonal antibody-based indirect competitive ELISA for detecting fluoroquinolone residues in milk

Modified 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) method was employed to synthesize the artificial antigen of norfloxacin (NOR), and New Zealand rabbits were used to produce anti-NOR polyclonal antibody (pAb). Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay (icELISA) standard curve was established. This assay was sensitive and had a working range from 0.12 to 68.40 ng/ml, with the half maximal inhibitory concentration (IC₅₀) and limit of detection (LOD) values of 2.7 ng/ml and 0.06 ng/ml, respectively. The produced pAb exhibited high cross-reactivity to fluoroquinolones (FQs) tested, and the IC₅₀ values to enoxacin, ciprofloxacin, and pefloxacin were 3.1, 3.4, and 4.1 ng/ml, respectively. It also indicated that the concentrations of NaOH and methanol in assay buffer should not be higher than 10% and 30%. When spiked in milk at 5, 20, and 50 ng/ml, the recoveries for NOR, enoxacin, ciprofloxacin, and pefloxacin ranged 90.5%–98.0%, 84.0%–95.2%, 94.0%–106.0%, and 89.5%–100.0%, respectively. The results suggest that this class-specific pAb-based icELISA could be utilized for the primary screening of FQ residues in animal-original products.     

Monoclonal antibody-based ELISA and colloidal gold-based immunochromatographic assay for streptomycin residue detection in milk and swine urine

A protein conjugate of streptomycin (streptomycin-bovine serum albumin (BSA) conjugate) was prepared and used as immunogen to produce monoclonal antibodies (MAb). One hybridoma secreting anti-streptomycin MAb was obtained and then used to produce MAb. The MAb named 13H5 showed the 50% maximal inhibitory concentration (IC50) value of 4.65 ng/ml and the IC20 value of 0.21 ng/ml in phosphate buffered saline (PBS). At optimum conditions, an indirect competitive enzyme-linked immunosorbent assay (ELISA) and a co...     

Development of an electrochemical immunoassay for detection of gatifloxacin in swine urine

To detect gatifloxacin (GAT) residue in swine urine, an electrochemical immunoassay was established. An indirect competitive immunoassay was developed, in which the coating antigen is immobilized in an enzyme-linked immunosorbent assay (ELISA) plate and GAT residue from the sample competes with the limited binding sites in added anti-GAT antibody. Horseradish peroxidase (HRP) conjugated to goat anti-rabbit IgG was used as the enzymatic label. A carbon fiber working electrode was constructed and current signals were detected by using hydrogen peroxide as a substrate and hydroquinone as an electrochemical mediator. The electrochemical immunoassay was evaluated by analysis of GAT in buffer or swine urine and an average value of half inhibition concentration (IC₅₀) of 8.9 ng/ml was obtained. Excellent specificity of the antibody was achieved with little cross-reaction with lomefloxacin (3.0%), ciprofloxacin (3.0%), and ofloxacin (1.9%) among commonly used (fluoro)quinolones. In conclusion, the immunoassay system developed in this research can be used as a rapid, powerful and on-site analytical tool to detect GAT residue in foods and food products.     

Preparation of high-affinity rabbit monoclonal antibodies for ciprofloxacin and development of an indirect competitive ELISA for residues in milk

A convenient competitive enzyme-linked immunosorbent assay (ELISA) for ciprofloxacin (CPFX) was developed by using rabbit monoclonal antibodies (RabMAbs) against a hapten-protein conjugate of CPFX-bovine serum albumin (BSA). The indirect competitive ELISA of CPFX had a concentration at 50% inhibition (IC₅₀) of 1.47 ng/ml and a limit of detection (LOD) of 0.095 ng/ml. The mAb exhibited some cross-reactivity, however, not so high with enrofloxacin (28.8%), ofloxacin (13.1%), norfloxacin (11.0%), fleroxacin (22.6%), and pefloxacin (20.4%). And it showed almost no cross-reactivity with other antibiotics or sulfonamides evaluated in this study. The competitive ELISA kit developed here could be used as a screening tool to detect and control illegal addition of CPFX in food products. This kit had been applied to milk detection and the recovery rates from samples spiked by CPFX were in a range of 63.02%–84.60%, with coefficients of variation of less than 12.2%.     

Dual flow immunochromatographic assay for rapid and simultaneous quantitative detection of ochratoxin A and zearalenone in corn,wheat, and feed samples

A one-step dual flow immunochromatographic assay (DICGA), based on a competitive format, was developed for simultaneous quantification of ochratoxin A (OTA) and zearalenone (ZEN) in corn, wheat, and feed samples. The limit of detection for OTA was 0.32 ng/ml with a detection range of 0.53?12.16 ng/ml, while for ZEN it was 0.58 ng/ml with a detection range of 1.06?39.72 ng/ml. The recovery rates in corn, wheat, and feed samples ranged from 77.3% to 106.3% with the coefficient of variation lower than 15%. Naturally contaminated corn, wheat, and feed samples were analyzed using both DICGA and liquid chromatography-tandem mass spectrometry (LC-MS/MS) and the correlation between the two methods was evaluated using a regression analysis. The DICGA method shows great potential for simple, rapid, sensitive, and cost-effective quantitative detection of OTA and ZEN in food safety control.     

水浴消解-原子荧光光谱法同时测定土壤中的砷和汞

目的：建立原子荧光光谱同时测定土壤中砷和汞的方法。方法：王水水浴消解土壤样品,在最佳仪器、反应条件下同时测定其中的砷和汞。结果：检出限：As：0.087ng/mL,Hg：0.0065ng/mL。线性范围：As：0ng/mL-20 ng/mL,相关系数0.9999;Hg：0ng/mL-4ng/mL,相关系数0.9996。精密度：测定10ng/mL As、2ng/mLHg混合标准试液得到的标准精密度（RSD）,砷1.6%、汞2.7%。样品加标回收率：As：95.5%-101.4%,Hg：92.5%-102.0%。结论：该方法具有较高的灵敏度、准确度、精密度和较低的检出限,满足了土壤样品中砷和汞的同时测定要求,同时也适合于食品、生物材料等样品的测定。     

Study on the serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) in patients with Helicobacter pylori Infection

Objective: To evaluate the interaction between serum levels of soluble intercellular adhesion molecule-1 (sICAM-1) and Helicobacter pylori (H. pylori) infection in patients with chronic gastritis and peptic ulcer. Methods: The serum levels of sICAM-1 in 205 patients with chronic gastric diseases were detected by ELISA method and the status of H. pylori was determined by histologic examination, RUT, 14C - UBT, and serology. The sera obtained from 18 healthy volunteers served as controls. Results: The serum levels of sICAM-1 were significantly higher in patients with H. pylori positive than those of H. pylori negative (889.43±32.52 ng/ml vs. 747.07±30.45 ng/ml, P<0.05). The serum levels of sICAM-1 in patients with mild, moderate and severe infection of H. pylori were 841.68±72.36 ng/ml, 905.43±37.59 ng/ml and 1012.54±49.34 ng/ml,respectively (P<0.05). The serum levels of sICAM-1 proved to be significantly correlated with the density of H. pylori colonization in gastric mucosa (rs =0.316, P<0.001). The serum levels of sICAM-1 in patients with chronic gastritis and peptic ulcer were significantly higher than those in healthy controls (P<0.05). Conclusions: These results indicated that H. pylori infection up-regulates the expression of sICAM-1.     

Determination of fluorinated quinolone antibacterials by ion chromatography with fluorescence detection

For preparing fluorinated quinolone antibiotic medicine locally used in stomatology, simultaneous determination of norfloxacin, ciprofloxacin, and enoxacin was carried out by multiphase ion chromatography with fluorescence detection. Quinolone antibiotics were separated by Dionex OmniPac PAX-500 column with an eluent of 15 mmol/L H2SO4 and 35% methanol （v/v） at a flow-rate of 1.0 ml/min and detected with fluorescence with excitation and emission wave lengths of 347 ran and 420 ran respectively. The detection limits （S/N=3） of norfloxacin, ciprofloxacin and enoxacin were 50, 105 and 80 ng/ml respectively. The relative standard deviations of retention time, peak area and peak height were less than 1.1% and good linear relationship resulted. The developed method was applied to pharmaceutical formulations and biological fluids.     

Evaluation of a water-soluble adjuvant for the development of monoclonal antibodies against small-molecule compounds

A water-soluble adjuvant named QuickAntibody (QA) was introduced into the procedure of mouse immunization for the development of hapten-specific monoclonal antibodies (mAbs), using four kinds of pesticides as model compounds. Compared with conventional Freund;’s adjuvants, QA treatments offered relatively low but acceptable antiserum titers after three inoculations, gave little adverse effects to the experimental animals, and were preferable in harvesting splenocytes during the steps of cell fusion. Afterwards, hybridomas from the QA group were prepared and screened by both non-competitive and competitive indirect enzyme-linked immunosorbent assays (ELISAs). The efficiency of gaining immune-positive hybridomas was satisfactory, and the resultant mAbs showed sensitivities (half maximal inhibitory concentration (IC₅₀)) of 0.91, 2.46, 3.72, and 6.22 ng/ml to triazophos, parathion, chlorpyrifos, and fenpropathrin, respectively. Additionally, the performance of QA adjuvant was further confirmed by acquiring a high-affinity mAb against okadaic acid (IC₅₀ of 0.36 ng/ml) after three immunizations. These newly developed mAbs showed similar or even better sensitivities compared with previously reported mAbs specific to the corresponding analytes. This study suggested that the easy-to-use adjuvant could be applicable to the efficient generation of highly sensitive mAbs against small compounds.     

基于纳米金／甲苯胺蓝／多壁碳纳米管复合物膜修饰的高灵敏的电流型癌胚抗原免疫传感器的研究

以固载于玻碳电极（GC）表面的壳聚糖／多壁碳纳米管（MWNT～CS）复合物膜为基底电聚合媒介体甲苯胺蓝（PTOB）,利用静电作用吸附纳米金（nano--Au）,再利用纳米金良好的生物兼容性、大的比表面积固定癌胚抗体（anti—AFP）,从而制得高灵敏、高稳定电流型癌胚抗原免疫传感器。多壁碳纳米管复合物膜促进了电子的传递．增大了电极的比表面积：纳米金的存在增加了抗体在电极表面的固定量,从而提高了免疫电极的灵敏度。在优化的实验条件下．该免疫电极在1．0～80．0ng／mL范围内,峰电流与CEA抗原的浓度呈良好的线性关系。检测线为0．4ng／mL。该免疫传感器制备方法简单,灵敏度高、选择性好。