高灵敏度电容型透明质酸结合蛋白免疫传感器的研制

实验用金电极自组装技术构建透明质酸结合蛋白电容型免疫传感器，采用交流阻抗技术对电极表面生物绝缘膜进行研究。按R(RC)等效电路图对其阻抗谱进行拟合的偏差较小，显示实际体系接近于拟合的电路图。该传感器对1-100mg/L抗原具有良好的线性响应。构建的生物膜对于一定范围的离子强度、酸度具有良好的稳定性，表明其有望应用于临床检测。     

基于巯基自组装单层膜技术的补体C3压电免疫传感器的研究

本文采用自组装单层膜(SAMs)技术在压电石英晶振金电极表面组装巯基丙酸SAMs,以盐酸1-乙基-3-(3-二甲基氨基丙基)碳二亚胺(EDC)和N-羟基琥珀酰亚胺(NHS)作偶联剂共价固定补体C3抗体,研制了一种检测人血清中补体C3成分的压电免疫传感器。研究了巯基丙酸的自组装和抗体的固定化条件,考察了晶振固定抗体后的液相振荡行为和检测特性。并利用压电传感装置的实时监测功能,研究了巯基丙酸在金电极表面的自组装成膜过程和补体C3免疫反应动力学,获得了重要的动力学依据和参数。传感器检测补体C3的线性范围为2．34～23．2μg／mL。将传感器用于临床样品的检测,所得结果与酶联免疫吸附法基本一致。     

无试剂金胶-半胱胺苯酚传感器研究

用电化学方法研究了金胶表面固定酪氨酸酶(Tyr)的直接电子传递行为和该修饰电极在苯酚分析方面的应用。金胶联接在半胱胺自组装单层尾部的氨基上。在pH7.0的0.1 mol/L磷酸盐缓冲溶液中,Tyr/金胶/半胱胺修饰电极上的Tyr进行直接电子传递,产生一对氧化还原峰。固定在金胶表面的Tyr的表面覆盖度为6.6×10-10mol/cm2。不需要电子媒介体的作用,该传感器对苯酚的还原具有较好的电催化作用。苯酚测定的线性范围为2.5μmol/L~5 mmol/L,检出限为0.8μmol/L(信噪比是3)。该传感器对苯酚的测定显示了良好的重复性。在高浓度的苯酚中,此传感器表现出Michaelis-Menten行为,KMapp为3.8 mmol/L。     

金表面自组装化学发光免疫传感器

用Ｎ－乙酰半胱氨酸金表面自组装技术及ＥＤＣ、ＮＨＳ偶联剂将兔ＩｇＧ固定于金表面制成免疫传感器探头，用碱性磷酸酯酶标记山羊抗兔ＩｇＧ加入待测的含有山羊抗兔ＩｇＧ的样品中，采用竞争头测定山羊抗兔ＩｇＧ含量，标记的碱性磷酸酯酶可催化底物ＡＭＰＰＤ产生化学发光，其发光强度与样品浓度成反比。测得山羊抗兔ＩｇＧ的最低检出限为０．８ｍｇ／Ｌ，线性测定范围为０．８－４０ｍｇ／Ｌ。     

压电免疫传感器用于乙肝表面抗原的测定

乙肝表面抗原 ( HBs Ag)的检测是临床诊断乙型肝炎的一项重要指标 .目前常用酶联免疫法和放射免疫法检测 [1] ,但酶本身性质不稳定且价格昂贵、操作繁琐 ;而放射免疫法存在放射性废物难处理的局限性 .压电免疫传感器具有装置简单、价格便宜、灵敏度高、实时快速和无需标记等优点 ,广泛应用于环境监测、药物分析及微生物检测等多个领域 [2～ 4 ] .本文应用自组装单分子膜技术 ,在压电石英晶体表面形成致密有序的半胱胺单分子膜 ,通过戊二醛共价交联 ,将乙肝表面抗原单克隆抗体分子固定于晶体电极表面 ,研制成 HBs Ag压电免疫传感器 ,用于…     

非标记液晶型免疫传感器检测赭曲霉素A

研制了一种基于液晶取向改变的非标记液晶型免疫传感器,并用于检测赭曲霉素A(0TA).采用戊二醛交联法将OTA同定在由自组装膜修饰的玻璃肇底表面.自组装膜能诱导液晶分子垂直排列,而连接OTA抗体后则扰乱了液晶分子取向的有序排列,导致液晶分子在化学敏感膜表面的取向发生变化,使光学信号的亮度及色彩发生变化,以此实现对OTA的...     

压电免疫传感器在梅毒检测中的研究

用巯基丙酸(MPA)为基层物质在压电石英晶体表面形成单分子膜,经过N-乙基-N′-(3-二甲氨基)丙基碳化二亚胺盐酸(EDC)和N-羟基琥珀酰亚胺(NHS）活化后固定梅毒抗原TpAg,制成免疫传感器检测不同浓度的标准抗体溶液。并考察了传感器的响应特性和免疫反应动力学特性,结果表明这种免疫传感器是临床检测的有效工具,有巨大的应用潜力。     

基于微机电系统技术和纳米金自组装膜的安培型免疫传感器研究

基于微机电系统(MEMS)技术制备安培型免疫传感器,并利用基于硫醇单层膜的纳米金单层膜自组装技术设计传感器界面,用于固定人免疫球蛋白(IgG)抗体,研制了一种新型的安培型免疫传感器。采用MEMS技术,在硅片上制备微型的三电极系统以及SU-8反应池。基于自组装技术,先在金电极上自组装巯基乙胺单层膜,利用膜上氨基与纳米金共价结合组装纳米金单层膜,得到可用于固定抗体的界面。实验探讨了影响抗体固定的主要实验参数和条件;考察了采用此固定化方法传感器的响应性能,与金电极直接吸附固定法和戊二醛共价交联固定法进行了比较。对IgG检测的实验结果表明,采用纳米金自组装膜固定抗体,具有活性高、非特异性吸附小、检测线性范围宽等优点。并且,基于MEMS技术的安培型免疫传感器具有微型化、与集成电路工艺相兼容、易于实现传感器的阵列化和实时多参数检测等优点。     

基于胱氨自组装膜的压电免疫传感器检测抗凝血酶Ⅲ

提出了一种基于胱氨自组装膜和采用聚电解质吸附法固定活性物质的压电免疫传感器，用于检测人血浆中抗凝血酶Ⅲ（AT－Ⅲ）。先在压电石英晶振的金电极表面自组装一层带疏基的胱氨单分子膜，再在膜上组装一层聚电解质褐藻酸钠（AAS），通过静电吸附作用，将AT－Ⅲ抗体固定于石英晶体表面，在含有3.5%聚乙二醇（PEG）的缓冲溶液中检测AT－Ⅲ。比较了传感器分别采用AAS吸附法和戊二醛键合法固定AT－Ⅲ抗体的响应性能，发现前者固定的抗体的活性较高，反应响应的频移值较大，检测的线性范围也较宽。实验采用PEG作免疫反应的促进剂，进一步改善了传感器的检测灵敏度和检测限。采用Piranha试剂作洗脱液可实现传感器的反复再生。干扰与回收率实验结果表明，该传感系统可用于人血浆中AT－Ⅲ的临床检测。     

双电层电容法在电化学生物传感器中的研究与应用

对双电层电容法在电化学生物传感器中的研究和应用进行了较全面的综述,并展望了其发展前景。     

A Piezoelectric Immunosensor for the Detection of Cortisol

Abstract

A piezoelectric crystal immunosensor has been developed for the detection and determination of cortisol. Cortisol antibody was layered onto the gold electrodes of a 10 MHz piezoelectric crystal which was precoated with either protein A or gluteraldehyde. Crystals pre-coated with protein A showed the best results with respect to stability and sensitivity.

The sensor was successfully used for the determination of cortisol in standard solutions from 36–3628 μg/L (part per billion). The advantages of the proposed sensor include simplicity, short analysis time, cost effectiveness and selectivity. The results demonstrate the feasibility of cortisol assay in clinical testing and in drug monitoring.     

Detection of Cocaine Using the Flow Immunosensor

Abstract

A continuous flow immunosensor has been designed for the detection of cocaine in aqueous samples. The continuous flow immunosensor relies on the displacement of fluorophore-labeled antigen from immobilized monoclonal antibody. The sensitivity and accuracy of the flow immunosensor were investigated while varying the parameters of immobilized antibody density, flow rate, amount of antibody-coated Sepharose used in each column, and the saturation of antibody binding sites with fluorophore-labeled antigen. Using a low density of immobilized anti-benzoylecgonine antibody, as little as 5 ng/ml cocaine could be detected. Small amounts of antibody-coated Sepharose could be used repeatedly and the lifetime of the column was proportional to the amount of Sepharose used. Results were obtained in less than a minute and cross-reactivity against various other drugs was negligible.     

多个时间常数线性体系暂态响应方程参数的代数求解法

从线性条件出发, 推导了含n个时间常数体系恒电位阶跃时暂态响应方程, 并提出一套解析形为ΔI=ΔI_∞+sum from i=1 to n k_iexp(-t/τ_i)暂态方程各未知参数的代数解法。该方法可对未知体系时间常数个数进行判定, 比起一般曲线拟合更加快速简便, 且抗干扰能力较强。     

Label‐Free Detection of Bisphenol A Using a Potentiometric Immunosensor

A potentiometric immunosensor for the label‐free detection of bisphenol A (BPA) was developed by covalently immobilizing a polyclonal antibody (PAb) onto the surface of a carboxylated poly(vinyl chloride) (PVC‐COOH) membrane. The immunosensor was characterized using scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy. The immobilization of PAb and its interaction with antigen (Ag) and BPA were also confirmed by quartz crystal microbalance (QCM) studies. Experimental parameters affecting the immuno‐interaction between PAb and its Ag or BPA were examined in terms of pH, antibody concentration, and temperature. The immunosensor showed a specific recognition of BPA with less interference than 4.8% from other common phenolic compounds. A calibration plot was obtained between 1.0 and 30.0 ng/mL and the detection limit was determined to be 0.6 ng/mL. The proposed immunosensor was applied for a real water sample spiked with BPA and the recoveries were in the range between 102.5 and 105.7%.     

微型电化学免疫传感器的研制及初步应用

利用微电子技术和电化学原理设计制作了一种微型电化学免疫传感器,应用恒电位法建立了该传感器的实验条件。在设定的实验条件下测试,阳性血清的电流响应曲线与阴性血清的电流响应曲线具有明显的离散度,并能检测不同类型的抗原抗体反应,不同抗原抗体之间没有交叉反应;测定一个样品用时不到1h,仅用血清10μL;传感器操作简便,微型小巧,便于携带,通过进一步的设计和条件优化,有望应用于临床和现场抗原抗体反应的快速检测分析和诊断。     

CdSe Quantum Dots Based Electrochemiluminescence Immunosensor with Simple Structure for Ultrasensitive Detection of Salbutamol

A rapid and ultrasensitive electrochemiluminescence (ECL) competitive immunoassay based on CdSe quantum dots (QDs) and the shorter chain as possible (cysteamine and glutaraldehyde) has been designed for the detection of salbutamol (SAL). Cysteamine and glutaraldehyde made coating antigen immobilize well on the gold electrode surface through the reaction between functional groups, which brought about the simplicity of the immunosensor to some extent. Transmission electron microscopy image, dynamic light scattering, photoluminescence, ultraviolet‐visible absorption and electrochemical impedance spectra were used to characterize the prepared CdSe QDs and the cysteamine/glutaraldehyde/Ovalbumin‐SAL/anti‐SAL‐QDs immunosensor. In the air‐saturated PBS buffer containing 0.1 M K₂S₂O₈ and 0.1 M KCl (pH 9.0), a strong ECL emission of QDs can be observed which depended linearly on the logarithm of the salbutamol concentration with a wide range from 0.05 ng mL^?1 to 100 ng mL^?1, and a detection limit of 0.0056 ng mL^?1. The sensitivity, repeatability, and specificity of the ECL immunosensor have been evaluated. The sensor has been applied to real samples with satisfactory results. This work will open new ways of detecting food additive residue based on QDs ECL in immunoassays.     

Development of Piezoelectric Immunosensor for the Detection of Probiotic Bacteria

A Quartz Crystal Microbalance (QCM) based direct immunosensor was developed for real-time detection of probiotic bacteria. To optimize the immunosensor system, model measurements were carried out with bovine serum albumin (BSA) and anti-BSA IgG (a-BSA) antibody. During the model experiments, two kinds of self-assembled monolayers were created to compare their efficiency on antigen binding. Sulfosuccinimidyl 6-[3-(2-pyridyldithio)propionamido] hexanoate (sulfo-LC-SPDP) and 16-mercapto-hexadecanoic acid (MHDA) cross-linking agents were used for immobilizing anti-BSA antibody onto the gold surface of the AT-cut quartz wafer. Two different measuring procedures, flow-through and stopped-flow methods, were applied, and the frequency responses obtained by both analytical methods were compared.

After the model experiments probiotic bacteria, Bifidobacterium bifidum O1356 and Lactobacillus acidophilus O1132 serotypes were detected from buffer solution and from real samples (spiked milk samples, acidophilus, and bifidus milk samples).

Using the novel immunosensor, the target bacteria could be detected in the range of 10⁴–10⁷ colony-forming units (CFU)/ml within 60 minutes. The selectivity of a-Bifidobacterium bifidum and a-Lactobacillus acidophilus antibody coated sensors were also tested.     

抗体固载于电聚合物膜的压电免疫型细菌传感器

采用电化学技术在镀银的压电石英晶体上沉积一层聚间苯三酚膜 ,用二乙烯基砜将其活化后 ,实现了特异性抗体 (抗肠道沙门氏菌抗体)在压电石英晶体上的固载 ,并用于肠道沙门氏菌的快速检测 ;其检出限为5×104cell/mL,检测时间为30min;该抗体固载技术简单易行 ,重复性好 ,并可用于价格低廉的镀银石英晶体 ,可望成为开发一次性压电型免疫检测探头的有效方法     

基于丝网印刷电极的阻抗型免疫传感器用于检测烯效唑

采用循环伏安法在丝网印刷碳电极表面电聚合聚苯胺/壳聚糖复合膜,利用静电吸附作用固定烯效唑抗体,制备了检测烯效唑的阻抗型免疫传感器.采用循环伏安法和电化学阻抗谱对电极修饰过程进行了表征,并考察了缓冲溶液pH值、温育温度及时间对免疫反应的影响.在优化的条件下研究了免疫传感器的性能.此免疫传感器具有灵敏度高、特异性强、重现性和稳定性好的特点,对烯效唑的线性检测范围为0.01 ～100 mg/L,相关系数为0.999,检出限为8μg/L(3σ).白菜样品中添加0.05,0.10和1.0 mg/kg烯效唑,平均回收率为98.5％ ～ 104.6％,相对标准偏差为3.3％ ～4.3％,检测结果与气相色谱法的检测结果相符.     

A Comparative Study of Voltammetric vs Impedimetric Immunosensor for Rapid SARS-CoV-2 Detection at the Point-of-care

Here, a novel biosensing platform for the detection of SARS-CoV-2 usable both at voltammetric and impedimetric mode is reported. The platform was constructed on a multi-walled carbon nanotubes (MWCNTs) screen-printed electrode (SPE) functionalized by methylene blue (MB), antibodies against SARS-CoV-2 spike protein (SP), a bioactive layer of chitosan (CS) and protein A (PrA). The voltammetric sensor showed superior performances both in phosphate buffer solution (PBS) and spiked-saliva samples, with LOD values of 5.0±0.1 and 30±2.1 ng/mL, compared to 20±1.8 and 50±2.5 ng/mL for the impedimetric sensor. Moreover, the voltammetric immunosensor was tested in real saliva, showing promising results.