可再生使用的溶胶-凝胶甲胎蛋白免疫传感器

可再生使用的溶胶-凝胶甲胎蛋白免疫传感器;溶胶-凝胶(sol-gel); 免疫传感器; 甲胎蛋白; 再生     

基于纳米银的检测黄曲霉毒素免疫传感器研究

黄曲霉毒素B1(AFB1)是食品中常见的强毒性霉菌毒素,如何对AFB1进行快速、准确、方便的检测受到了研究人员的广泛关注。本研究采用氧化石墨烯/纳米银/AFB1单克隆抗体复合材料(GO/Ag/AFB1抗体)修饰的金电极作为工作电极,利用纳米银良好的导电性实现较低的AFB1检出限。该免疫传感器在pH为7、温度为40℃、抗体与PBS体积比为1∶6000的最优条件下,无需添加信号放大物质,检出限最低可达到7.19×10~(-10 )μg·kg~(-1),检测范围为1.60×10~(-9)～1.68×10~(-5)μg·kg~(-1),孵育时间为30s,回归方程为y=1.3101ln(x)+30.817(R~2=0.9916),测得含有AFB1实际玉米样品的回收率为91.42～107.00%。结果表明,GO/Ag/AFB1抗体免疫传感器具有在无需添加信号放大物质的情况下操作简便、响应迅速、灵敏度高、检出限低等特点,有望应用于食品领域AFB1的实时检测。     

黄曲霉毒素电化学生物传感器

黄曲霉毒素（aflatoxin,AF）是一种具有强烈毒性和强致癌性的生物毒素,对其进行快速而准确的分析是减小和避免黄曲霉毒素危害的最有效手段之一。电化学生物传感器因其快速、灵敏、特异性强、易于微型化等优势在黄曲霉毒素分析受到国内外研究者的广泛关注。目前,应用于黄曲霉毒素分析的电化学生物传感器主要有免疫传感器、酶传感器和DNA传感器。本文综述了不同传感器的研究现状,特别介绍了新材料新技术在黄曲霉毒素免疫分析中发挥的重要作用,并对黄曲霉毒素的电化学生物传感分析存在的问题和发展前景进行了探讨及展望。     

基于功能化溶胶-凝胶膜的乳腺癌抗原免疫传感器

结合溶胶-凝胶(sol-gel)和交联技术,将乳腺癌抗体固定在铂盘电极表面的氨基化sol-gel功能膜上,制备出用于检测乳腺癌抗原(CA15-3)的免疫传感器.用红外光谱验证了该传感器功能膜的形成过程和组成结构,采用循环伏安法对传感器逐层修饰过程进行了表征,并对传感器功能膜的作用机理进行了探讨.该法检测CA15-3的线性范围为8～240U/mL,线性回归方程为ΔE=75.75lgc-56.36,r=0.998.结果表明,该方法很好地保持了被固定抗体的活性,增强了传感器的稳定性,所制备的传感器于4℃干态保存30d,其响应信号基本不变.且该传感器响应迅速、灵敏度高、选择性好,血清中常见抗原不干扰测定.     

溶胶-凝胶非标记免疫传感器检测乙肝表面抗原

采用溶胶 凝胶 (sol gel)技术包埋乙肝表面抗体 (HBsAb) ,涂布于金盘电极表面 ,构成sol gel HBsAb/Au非标记免疫传感器 ,用于检测人血清中乙肝表面抗原 (HBsAg)。该传感器对HBsAg的电位响应遵循Nernst方程 ,在 1～ 330 μg/L浓度范围内 ,传感器的电位响应值ΔE与HBsAg浓度C的对数呈线性关系 ,线性回归方程为ΔE =1 8.1 7+79.84lgC。响应时间为 3min。癌胚抗原、甲胎蛋白等对测定无明显影响。对于HBsAg阴性血清 ,电位响应值ΔE <30mV ,而对于阳性血清则ΔE >30mV ,据此 ,作为临床判别的依据。对1 0 0例临床血清分别用传感器和酶联免疫法 (ELISA)进行双盲检验 ,两法的符合率为 86 %。     

基于ZnO溶胶-凝胶固定的酪氨酸酶传感器的研制

通过使用带正电荷的ZnO溶胶-凝胶在玻碳电极表面固定酶,研制了一种简单有效的酪氨酸酶传感器。结果表明,ZnO溶胶-凝胶的等电点为酪氨酸酶的固定提供了有利的微环境,酪氨酸酶能很好地保持其生物活性。所研制的传感器达到95%稳定状态电流的时间在10 s以内。酚类化合物可通过酶催化产生的醌在-200 mV(对饱和甘汞电极)直接还原而测定,传感器对苯酚测定的灵敏度为168μA.mmol-1.L-1,线性范围为1.5×10-7~4.0×10-5mol.L-1,检出限为8.0×10-8mol.L-1。该传感器使用二周后活性仍保持原有活性的75%。     

三氧化二铝溶胶-凝胶固定过氧化氢生物传感器

三氧化二铝溶胶凝胶将辣根过氧化物酶和硫堇同时固定在玻碳电极上,紫外-可见光谱结果表明酶在固定过程中生物活性保持得较好.传感器在pH 7.0外加电压为-0.22 V条件下,对过氧化氢浓度为1.76×10-3～5.5×10-2 mol/L的范围内呈线性响应,检出限为1.1×10-4 mol/L.传感器的选择性和稳定性较好,使用3个星期后,仍能保持其初始活性的80%.     

溶胶-凝胶-HBsAb膜免疫传感器的研制与应用

采用溶胶-凝胶(Sol-gel)技术,成功地将乙肝表面抗体(HBsAb)包埋于Sol-gel中,再滴涂于铂盘电极表面,制成溶胶-凝胶-HBsAb膜非标记免疫传感器.根据抗原与抗体特异性结合形成的免疫复合物使敏感膜有效扩散截面积减小的特性,提出了利用铁氰化钾作为氧化还原探针间接检测乙肝表面抗原(HBsAg)的新方法.用循环伏安法(CV)对电极逐层修饰过程进行了表征,并探讨了对HBsAg定量检测的可行性及其响应机理.采用差示脉冲伏安法(DPV)检测人体血清中的HBsAg.线性范围5～320μg/L,线性相关系数r=0.997.该传感器响应迅速,灵敏度高,稳定性好.于4℃干态保存14d,其响应信号基本不变.将其用于108例临床血清检验,与酶联免疫吸附法(ELISA)的符合率为87.5％.     

溶胶凝胶技术在生物传感器中的应用

溶胶凝胶过程以基纯度高,均匀性强,处理温度低,反应条件易于控制等优点,已被成功地用以生物组分的固体上。溶胶凝胶技术作为一种颇具前任的固化方法,为生物传感器的制作和发展提供了更多的机会和条件,本文就近几年间溶胶凝胶技术在生物传感器中的开发应用状况进行了综述。     

溶胶-凝胶生物传感器

评述了溶胶－凝胶生物传感器这个领域已取得的成果,主要内容涉及溶胶－凝胶固定化方法的过程,优点与性质,溶胶－凝胶光学生物传感器和安培生物传感器的发展,并展望了其发展趋势。     

单克隆抗体亲和柱分离荧光法测定花生和玉米中黄曲霉毒素B1的研究

本文建立了用单克隆抗体亲和柱分离荧光法测定花生和玉米中黄曲霉毒Ｂ１的方法，用６０％甲醇提取样品中的ＡＦＴ，经氢氧化铁沉淀除去大部分杂质，通过亲和柱将ＡＴＦＢ１进一步与杂质分离，甲醇洗脱后加溴处理，测定荧光强度，与标准比较定量。     

用高效液相色谱测定食物中维生素B_1、B_2含量

本文着重介绍使用高效液相色谱荧光测定天然食品中维生素B_1、B_2含量。在测试维生素B_1时,使用键合C_(18)分析柱,流动相为CH_3OH-0.01M KH_2PO_4 45/55,流速1.5ml/min,Ex:390nm,EM:470nm,柱温45℃;测维生素B_2时用强阳离子交换柱,流动相CH_3OH/0.01M KH_2PO_4,CH_3OH由30～70分钟梯度淋洗,流速1.5ml/min,柱温45℃,Ex:449nm,EM:530nm。在上述条件下所测部分食物中维生素B_1的回收率是92.51～101.85%,变异系数2.14～6.57%;维生素B_2的回收率为89.91～95.18%,变异系数0.19～6.19%。部分食物样品的测试结果令人满意。     

黄曲霉毒素B1抗体和纳米金颗粒的相互作用机理

研究了纳米金标黄曲霉毒素B1单克隆抗体(McAb)探针的制备及其标记机理, 确定了稳定标记5种不同粒径金溶胶(10.7~67.4 nm)所需McAb的最适质量浓度, 分别为0.07, 0.051, 0.033, 0.019, 0.012 mg/mL, 作用时间为5 min, pH为7.4. 对金标探针复合物进行透射电镜、红外光谱和免疫反应性鉴定的结果表明, 与未标记抗体相比, 抗体探针的免疫亲和常数、效价和常温贮藏稳定性得到了明显提高. 通过荧光光谱和圆二色谱研究纳米金与AFB1单抗McAb的相互作用机理, 发现纳米金对McAb产生静态猝灭, 猝灭的速率常数随着温度升高而降低. 确定了结合位点数和结合常数. 结果显示, 表明McAb的色氨酸残基与纳米金颗粒之间发生了Förster偶极-偶极无辐射能量转移. 初步确定反应前后McAb构象组成发生了变化是McAb探针亲和力和稳定性提高的原因.     

Applications of Amperometric Silica Sol-Gel Modified Enzyme Biosensors

ABSTRACT

The applications of amperometric sol-gel modified enzyme biosensors in numerous analyses of clinical, industrial and environmental importance have been demonstrated. Certain biosensors have been employed as the sensor in a FIA amperometric detector. The results obtained by the biosensors generally corroborate well with the classical or official method. In many cases, the recovery results obtained by the biosensor have been satisfactory.     

三维荧光光谱总体积积分法同时测定维生素B2和B6

运用三维荧光光谱总体积积分法建立了一种测定维生素Ｂ２和Ｂ６的荧光分析新方法，该方法的度较常规峰值法分别提高１３０和３１０倍，同时成功地应用于两者的同时测定。     

Molecular Recognition of Aflatoxin M1 in Water and Milk Samples

Two stochastic microsensors based on diamond paste modified with 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) were proposed for the molecular recognition of aflatoxin M1 in water and milk samples. Two types of diamond were used: a monocrystalline diamond powder (1 μm) (DP) and a nanopowder of monocrystalline diamond (10 nm) (nDP) for the design of the stochastic microsensors. The microsensors were incorporated as combined stochastic microsensors (a microcell containing the stochastic microsensor and the Pt wire, and a Ag/AgCl sensor) in a platform used for monitoring of waste waters and milk samples. The platforms were used for the fast screening of water and milk samples for the qualitative and quantitative analysis of aflatoxin M1 at very low concentration levels (up to 0.001 fg/L). The linear concentration ranges were wide, being able to cover concentrations between 0.001 fg/L to 20 μg/L. The highest sensitive microsensor (sensitivity of 4.74×10¹⁰ s mg^?1 L) was the one based on nDP. The results provided by the platforms were in agreement with those obtained by utilization of standard method (ISO certified methods (HPLC/fluorescence method)), recoveries being higher than 99.00 % and RSD lower than 1.00 % proving that the method can be reliable used for molecular recognition of aflatoxin M1 in water and milk samples.     

Spectrophotomeric Assay of Aflatoxin B1 Using Acetylcholinesterase Immobilized on Standard Microplates

Aflatoxins are a group of hepatotoxic secondary metabolites produced by molds Aspergillus. During inappropriate storage or processing of food and beverages, aflatoxins can be distributed and become a serious health problem. Disparate analytical techniques were prepared for the assay in the past. Here, a method based on inhibition of enzyme acetylcholinesterase (AChE) is performed allowing fast and simple prove of aflatoxins presence. For the assay purposes, AChE was immobilized on standard polystyrene microplates using gelatin as a stabilizing substance. Both free and immobilized AChEs were used and compared one to each other. Immobilization protocol was optimized and interference of organic solvents such as methanol was tested. For the immobilized AChE, limit of detection 2.75 ppb for aflatoxin B1 was received. The immobilized AChE kept full activity at least one month. Suitability of the assay for a practical performance is considered.     

维生素B1对细胞色素C电化学反应的影响

本文探讨了细胞色素Ｃ在维生素Ｂ１修饰金电极上的电化学反应，结果表明维生素Ｂ１是细胞色素Ｃ电化学反应很好的促进剂而且它的促进作用与金电极表面维生素Ｂ１分子数量相关。     

反相高效液相色谱法测定乳品及乳制品中的黄曲霉毒素M_1

采用反相高效液相色谱测定乳品及乳制品中黄曲霉毒素M_1(AFM_1)的含量。样品经氯仿提取,过硅胶固相萃取柱净化,用氯仿-丙酮(1+1)混合溶液将黄曲霉毒素M_1从固相萃取柱上洗脱下来。以ZORBAX SB C_(18)色谱柱为分离柱,水和乙腈为流动相梯度淋洗,用荧光检测器检测,外标法定量。黄曲霉毒素M_1在1.0～25μg·L~(-1)质量浓度范围内与其峰面积呈线性关系,检出限(3S/N)为0.05μg·kg~(-1)。应用此法测定了牛奶和乳粉中AFM_1的含量,并测得其平均回收率分别在76.0%～80.0%和76.7%～90.8%之间,相对标准偏差(n=6)均小于7.0%。     

A Novel Electrochemical Method for the Sensitive Determination of Aflatoxin B1 Using a Bivalent Binding Aptamer-cDNA Structure

In this study, a simple electrochemical sensing platform with the employment of a bivalent binding aptamer-cDNA probe (BBA-cDNA) structure is constructed for the detection of aflatoxin B₁ (AFB₁) as a mycotoxin. The BBA-cDNA structure is composed of two strands of aptamer (Apts) and their complementary strand (CS). Using a simple but accurate design, the presented measurement approach showed enhanced sensitivity and selectivity for AFB₁ detection with a LOD of 0.1 ng/mL. The approach presented in this study can be applied to the development of biosensors for the measurement of various toxins by substituting the proper aptamers and complementary strands.