酶联免疫吸附分析法测定水中双氯芬酸钠

本研究报道一种高灵敏度的测定自来水和表面水中药物残留双氯芬酸钠含量的间接酶联吸附分析法(ELISA)。在包被抗原为20μg/L,抗体为1∶20000倍稀释,辣根过氧化物酶-羊抗兔IgG为1∶20000倍稀释的优化条件下,双氯芬酸钠的检出限(LOD)为0.004μg/L~0.008μg/L,IC50值(标准曲线中吸光度抑制至最大吸光度值的50%时所对应的待测物浓度)为0.03μg/L~0.12μg/L。双氯芬酸钠在自来水中和表面水中的回收率分别为96%和113%。表面水存在一定的基体效应,但仅需要简单过滤稀释就可以消除。     

酶联免疫吸附分析法测定食品中的苏丹红I号

本研究建立了测定食品中苏丹红I号含量的间接竞争酶联免疫分析法。首先对苏丹红I号分子作了的修饰，再与载体蛋白交联制得免疫原和包被抗原，经动物免疫制得抗苏丹红I号的抗体。在包被抗原为100μg／L，抗体为1：100，000倍稀释，标记二抗为1：15000倍稀释的优化条件下，测得检出限为0．12μg／L，IC50值（标准曲线中吸光度抑制至最大吸光度值的50％时所对应的待测物浓度）为0．74μg／L。苏丹红I号在番茄酱和辣椒面中的回收率分别为106％和110％。样品仅需甲醇萃取再用缓冲液简单稀释就可以直接进行ELISA测定。     

酶联免疫吸附分析法测定食品中的苏丹红Ⅰ号

本研究建立了测定食品中苏丹红Ⅰ号含量的间接竞争酶联免疫分析法。首先对苏丹红Ⅰ号分子作了的修饰,再与载体蛋白交联制得免疫原和包被抗原,经动物免疫制得抗苏丹红Ⅰ号的抗体。在包被抗原为100μg/L,抗体为1:100,000倍稀释,标记二抗为1:15000倍稀释的优化条件下,测得检出限为0.12μg/L,IC50值(标准曲线中吸光度抑制至最大吸光度值的50%时所对应的待测物浓度)为0.74μg/L。苏丹红Ⅰ号在番茄酱和辣椒面中的回收率分别为106%和110%。样品仅需甲醇萃取再用缓冲液简单稀释就可以直接进行ELISA测定。     

酶联免疫吸附分析法测定环境水样中痕量药物吲哚美辛

将吲哚美辛与蛋白质载体结合,制成完全免疫抗原,经过多次动物免疫得到了性能优良的兔抗吲哚美辛抗体,在优化实验条件的基础上,建立了灵敏度高、特异性强、简便、稳定的测定水样中吲哚美辛的酶联免疫吸附分析方法(ELISA).IC50值(标准曲线中吸光度抑制至最大吸光度值的50%时所对应的待测物浓度)为0.09μg/L～0.17 μg/L,最低检出限为 0.005μg/L～0.01 μg/L.真实水样中,均发现含有吲哚美辛,浓度在0.016 μg/L~0.083 μg/L之间,水样的加标回收率在84.4%～127.0%之间.     

食品中三唑酮的酶联免疫吸附分析

制备人血清白蛋白和三唑酮的结合物作为免疫原,免疫兔子获得了抗三唑酮的抗体,并建立了三唑酮的酶联免疫吸附分析法。此方法被成功的应用于黄瓜、梨等食品中三唑酮的分析,最低检出限为40ng/g样品,回收率为92.44％～98.18％。并与气相色谱分析结果有很好的一致性。     

酶联免疫吸附分析法测定水样中的阿特拉津

应用阿特拉津半抗原衍生物共价交联于载体蛋白分子上，制成免疫抗原，经免疫得到高质量的兔抗阿特拉津抗血清。经条件优选，建立了测定阿特拉津的酶联吸附分析竞争法，测定性范围为０．０５－５．００μｇ／Ｌ，最低检出限仅为０．０１８－０．０２２μｇ／Ｌ，且精密度高，特异性强。     

直接竞争酶联免疫吸附分析法测定氰戊菊酯

采用活性酯法,将氰戊菊酯半抗原N-[2-(4-氯苯基)-3-甲基丁酰基]-4-氨基丁酸与载体蛋白共价偶联合成突出氰戊菊酯分子结构特征的人工抗原和包被原.以人工抗原免疫新西兰白兔制备抗血清,采用(NH4)2SO4分步盐析和DEAE纤维素柱层析法从抗血清中分离纯化对氰戊菊酯具特异性亲和力的抗体,采用活性酯法,以辣根过氧化物酶标记半抗原N-[2-(4-氯苯基)-3-甲基丁酰基]-6-氨基己酸.采用固定抗体、氰戊菊酯和酶标半抗原直接竞争结合固相抗体的模式, 建立对氰戊菊酯具高特异性的酶联免疫吸附分析方法.在优化条件下, 测定氰戊菊酯标样检测的线性浓度范围为0.001～10.0 mg/L; 检出限0.001 mg/L; 相对标准偏差(RSD, n=5)为9.19%.小白菜中分别添加0.10和5.0 mg/kg氰戊菊酯,直接竞争酶联免疫吸附分析法(ELISA)测定,重复6次,回收率分别为83.8%～109%和93.6%～110%; RSD分别为11.7%和7.25%.对实际样品的有效检出限为0.007 mg/L.其它常用拟除虫菊酯类杀虫剂(氯氰菊酯、溴氰菊脂、功夫菊酯、醚菊酯、联苯菊酯)不干扰氰戊菊酯的测定.     

氟甲喹单克隆抗体制备、鉴定及间接竞争酶联免疫吸附分析法

以氟甲喹(FLU)为原料,合成4个碳原子手臂的半抗原(FLUABA),采用活泼酯法与牛血清白蛋白(BSA)偶联制备免疫抗原,通过免疫Balb/c小鼠及细胞融合,获得1株稳定分泌抗氟甲喹单克隆抗体的杂交瘤细胞株DB6-E7,其抗体亚类为IgG1,亲和力常数(KA)为8.19×108L/mol。将氟甲喹、FLUABA及6个碳原子手臂的半抗原FLUACA分别与卵清白蛋白(OVA)偶联作为包被抗原,研究异源包被对间接竞争ELISA灵敏度的影响。结果表明,异源包被可显著提高ELISA方法的灵敏度。基于最佳异源包被(FLU-OVA)的酶联免疫吸附分析法的IC50为26.33μg/L,检出限为4μg/L,定量检测范围为8.0～114μg/L(IC20～IC80)。与喹诺酮类药物及结构类似物几乎不存在交叉反应,特异性高。此方法可满足畜禽产品中氟甲喹残留的快速筛查。     

基于荧光体系的酶联免疫吸附分析法的研究进展

酶联免疫吸附分析（Enzyme linked immunosorbent assay, ELISA）作为一种重要的免疫分析方法,具有高通量、信号读取方便、操作简单和成本低廉等优点,广泛应用于环境监测、食品安全检测以及医疗诊断等领域。然而,由于受比色显色原理的限制,传统ELISA的检测灵敏度难以提高。为了解决此问题,研究者开发了多种类型的新型检测体系。其中,荧光方法由于具有灵敏度高、操作简单以及响应快速等优势,引起了广泛关注。目前,多种新型荧光材料已被广泛用于构建ELISA,促进了ELISA在分析化学和生物医疗检测中的应用。本文详细介绍了有机小分子、硅/碳纳米粒子、金属纳米簇和量子点等荧光材料构建的ELISA,根据使用标记酶的不同,介绍了以碱性磷酸酶、辣根过氧化物酶等酶作为标记酶的ELISA,评述了近五年来荧光材料在构建ELISA方面的研究进展,并对其应用前景与发展趋势进行了展望。     

酶联免疫吸附分析法在植物病毒检测中的应用

结合作者工作，综述了酶联免疫吸附分析法（ELISA）在植物病毒检测中的应用。对ELISA的基本类型，改进和提高灵敏度的方法进行了分析，并阐述了该技术的某些发展趋势。引用文献29篇。     

Development of a PRiME cartridge purification method for rapid determination of malachite green and leucomalachite green in Chinese softshell turtle

A high‐throughput PRiME (process, robustness, improvements, matrix effects, ease of use) sample purification procedure was developed to simplify the multiple steps of traditional SPE in extracting the malachite green and leucomalachite green in Chinese softshell turtle (Pelodiscus sinensis). The sample loading volume, extracting solvent type, and pH value of the employed PRiME hydrophilic‐lipophilic balance cartridge for sample purification were optimized to be 3 mL, acetonitrile, and pH 5, respectively. In comparison with traditional SPE, the PRiME process is cost‐effective, solvent‐saving, and simple to operate, which only consists of a passing through step without traditional sorbent conditioning and impurity washing. Afterward, eluate was analyzed by ultra‐performance liquid chromatography‐tandem mass spectrometry, and the proposed method was validated for linearity (R² > 0.9992), intraday precision (2.44–3.22%), interday precision (3.28–6.58%), sensitivity (LOD ≤ 0.18 μg/kg and, LOQ ≤ 0.60 μg/kg), and recovery (88.7–94.1%, RSD < 6.79%). The results indicated that the PRiME technique can simplify the sample preparation procedure by avoiding the tedious steps, such as conditioning, washing, etc. It would be of significant interest for environmental and food safety applications in the market of Chinese softshell turtle and related products.     

Production of malachite green oxalate and leucomalachite green reference materials certified for purity

Malachite green oxalate (MG oxalate) and leucomalachite green (LMG) have been prepared and certified as pure reference materials. The purities of MG oxalate and LMG were assessed by high-performance liquid chromatography–diode array detection (HPLC–DAD), nuclear magnetic resonance (NMR) spectroscopy, differential scanning calorimetry (DSC), Karl Fischer titration, ashing and thermogravimetric analysis (TGA). MG oxalate was purified by supercritical fluid extraction (SFE). Prior to purification, commercial MG oxalate purity was estimated to be about 90%. The main impurities present in SFE-purified MG oxalate were identified and quantified using HPLC–DAD. The main impurities were found to be monode-MG (monodemethylated MG oxalate synthesis impurity), 4-(dimethylamino)benzophenone (4-DMABP), MG-carbinol and LMG. The homogeneity of both reference materials was also determined. Issues associated with the stability of LMG and MG oxalate in solution forced an extensive study investigating different parameters i.e. solvent, acid, analyte concentration and temperature. MG oxalate (100 μg/mL) was found to be stable in acetonitrile containing 1% v/v glacial acetic acid for at least 155 days and LMG (100 μg/mL) was stable in acetonitrile for at least 133 days. The final purity value for MG oxalate was 94.3 ± 1.4% m/m at the 95% confidence interval (or 67% m/m if MG cation is reported). For LMG, the certified purity was found to be 98.8 ± 0.8% m/m at the 95% confidence interval. Figure Calibration reference materials for malachite green and leucomalachite green, certified for purity, are essential in characterising these key analytes in a fish matrix reference material     

Monoclonal antibody-based enzyme-linked immunosorbent assay for detection of total malachite green and crystal violet residues in fishery products

A rapid easy-to-use trace level direct competitive enzyme-linked immunosorbent assay (dc-ELISA) detection of total residual malachite green (MG), crystal violet (CV) and their corresponding primary metabolites leucomalachite green (LMG) and leucocrystal violet (LCV) in fishery products in a single assay was developed. The monoclonal antibodies, anti-MG and anti-CV mAbs, were prepared using carboxyl-malachite green (CMG) and cationized bovine serum albumin (cBSA) conjugates as immunogen. The linear range for the quantitative detection of total MG, CV and their primary metabolites LMG and LCV was between 0.15 to 4.5?ng?mL^?1 with a half maximal inhibitory concentration (IC₅₀) at 0.56?±?0.04?ng?mL^?1 (n?=?5). The anti-MG mAbs exhibited 98% cross-reactivity to CV, less than 0.1% cross-reactivity with LMG and LCV, and no cross-reactivity with chloramphenicol, enrofloxacin, sulfadiazine, and tetracycline. Application of the dc-ELISA in fish tissue samples gave a limit of detection (LOD) of 0.37?ng?g^?1. The improved total detection lead to a recovery of 74.60?±?8.38% at 0.5?ng?g^?1 and 87.47?±?12.83% at 2.0?ng?g^?1 that was better than existing techniques. The dc-ELISA showed total MG in 7 out of 44 field fish samples that were confirmed with LC-MS/MS. The easy-to-use, inexpensive, and rapid dc-ELISA for the detection of total MG, CV and their corresponding primary metabolites holds promise for field applications.     

Magnetic solid‐phase extraction for determination of the total malachite green,gentian violet and leucomalachite green,leucogentian violet in aquaculture water by high‐performance liquid chromatography with fluorescence detection

In this study, magnetic multi‐walled carbon nanotube nanoparticles were synthesized and used as the adsorbent for the sums of malachite green, gentian violet and leucomalachite green, leucogentian violet in aquaculture water samples followed by high performance liquid chromatography with fluorescence detection. This method was based on in situ reduction of chromic malachite green, gentian violet to colorless leucomalachite green, leucogentian violet with potassium borohydride, respectively. The obtained adsorbent combines the advantages of carbon nanotubes and Fe₃O₄ nanoparticles in one material for separation and preconcentration of the reductive dyes in aqueous media. The structure and properties of the prepared nanoparticles were characterized by transmission and scanning electron microscopy, X‐ray diffraction, and Fourier‐transform infrared spectroscopy. The main parameters affecting the adsorption recoveries were investigated and optimized, including reducing agent concentration, type and amount of sorbent, sample pH, and eluting conditions. Under the optimum conditions, the limits of detection in this method were 0.22 and 0.09 ng/mL for malachite green and gentian violet, respectively. Product recoveries ranged from 87.0 to 92.8% with relative standard deviations from 4.6 to 5.9%. The results indicate that the sorbent is a suitable material for the removal and concentration of triphenylmethane dyes from polluted environmental samples.     

A highly sensitive and specific polyclonal antibody-based enzyme-linked immunosorbent assay for detection of antibiotic olaquindox in animal feed samples

The use of olaquindox (OLA) as an additive in animal feedstuffs has been prohibited in the European Union and many other countries. In this study, a highly sensitive and specific indirect competitive enzyme-linked immunosorbent assay (ELISA) for determination of OLA in animal feed samples was developed. OLA was activated by N′N-carbonyldiimidazole and coupled with bovine serum albumin (BSA) and ovalbumin (OVA). It was found that the sensitivity and specificity of the two antisera were very similar, with the IC₅₀ values of 16 ng mL⁻¹ and 19 ng mL⁻¹, respectively. Cross-reactivity was less than 35% for four structurally related compounds and no recognition of five other antibiotics was observed. The better antiserum I was selected for further experiments, for example testing stability, solvent effect, accuracy, and precision. The IC₅₀ value for eight standard curves was in the range 12–18 ng mL⁻¹ and the LOD at a signal-to-noise ratio of 3 (S/N = 3) was 0.31 ± 0.11 ng mL⁻¹. The ELISA tolerated 5% methanol without significant influence on IC₅₀ value. The recoveries of spiked OLA in five different animal feed types including auxin, pig complex feed, fish complex feed, broiler concentrated feed, and pig premix feed were in the range 88.3–119.0% and the intra-assay relative standard deviation (RSD) was within 4.7–33.5% (n = 3). The ELISA for unspiked feed samples was confirmed by high-performance liquid chromatography (HPLC), with a high correlation coefficient of 0.9862 (n = 5). The proposed ELISA could be a feasible quantitative/screening method for OLA analysis in feed samples with the properties of high sensitivity, specificity, simplicity of sample pretreatment, high sample throughput, and low expense. Figure Polyclonal antibody based ELISA for detection of olaquindox     

Spectrophtometric determination of malachite green in fish farming water samples after cloud point extraction using nonionic surfactant Triton X-100

A novel and sensitive cloud point extraction procedure for the determination of trace amounts of malachite green by spectrophotometry was developed. Malachite green was extracted at pH 2.5 mediated by micelles of nonionic surfactant Triton X-100. The extracted surfactant-rich phase was diluted with ethanol and its absorbance was measured at 630 nm. The effect of different variables such as pH, Triton X-100 concentration, cloud point temperature and time and diverse ions was investigated and optimum conditions were established. The calibration graph was linear in the range of 4-500 ng mL⁻¹ of malachite green in the initial solution with r = 0.9996 (n = 10). Detection limit based on three times the standard deviation of the blank (3S_b) was 1.2 ng mL⁻¹ and the relative standard deviation (R.S.D.) for 20 and 300 ng mL⁻¹ of malachite green was 1.48 and 1.13% (n = 8), respectively. The method was applied to the determination of malachite green in different fish farming and river water samples.     

An enzyme-linked immunosorbent assay for aconitine-type alkaloids using an anti-aconitine monoclonal antibody

3-Succinylaconitine was conjugated with bovine serum albumin (BSA) for use as an immunogen for the preparation of a monoclonal antibody (MAb) against aconitine (Aco). Splenocytes from mice immunized with the Aco-BSA conjugate were fused with an aminopterin-sensitive mouse myeloma cell line, P3-X63-Ag8-653, and a hybridoma secreting a MAb against Aco was successfully obtained. The MAb cross-reacted with mesaconitine, hypaconitine and jesaconitine, which are Aco-type alkaloids, but not with any other compounds examined. The full measurement range of an enzyme-linked immunosorbent assay (ELISA) developed using the new MAb extended from 100 ng mL⁻¹ to 1.5 μg mL⁻¹ of Aco. The concentrations of Aco-type alkaloids in various Aconiti radixes assayed using the new ELISA method showed good agreement with previous reports.     

Biological monitoring of 3-phenoxybenzoic acid in urine by an enzyme-linked immunosorbent assay

An enzyme-linked immunosorbent assay (ELISA) method was employed for determination of the pyrethroid biomarker, 3-phenoxybenzoic acid (3-PBA) in human urine samples. The optimized coating antigen concentration was 0.5 ng/mL with a dilution of 1:4000 for the 3-PBA antibody and 1:6000 for the enzyme conjugate. Urine samples were hydrolyzed with concentrated hydrochloric acid; extracted with dichloromethane and solvent-exchanged into a methanol/buffer solution, prior to analysis in a 96-microwell plate immunoassay. Quantitative recoveries of 3-PBA were obtained for fortified urine samples by ELISA (92 ± 18%) as well as by gas chromatography/mass spectrometry (GC/MS) (90 ± 13%). The overall method precision of these samples was within ±20% for both the ELISA and GC/MS methods. Analytical results from over one hundred urine samples showed that the ELISA and GC/MS data were highly correlated, with a correlation coefficient of 0.95. At the 10 ng/mL comparative concentration level, the false positive rate was 0% and the false negative rate was 0.8% for ELISA when using GC/MS as the reference method. The ELISA method has a suitable low detection limit for 3-PBA to assess pyrethroid exposures in non-occupational settings.