Screen‐printed biosensor for allergens

Allergen levels in indoor environments, leading to many diseases, eg asthma, rhinitis and conjunctivitis, affect a large and increasing fraction of the population. A quite effective and inexpensive method of a rough but very rapid overall assessment of total allergen level in the environment has been developed. The method involved estimation of protein in allergen extracts by screen‐printed electrodes using two different techniques. The biosensor comprised a rhodinised carbon working electrode, a silver/silver chloride reference electrode and a carbon counter electrode. In the first method the enzyme protease reacted with allergen protein to release amino acid, which produced hydrogen peroxide in the presence of amino acid oxidase. This was detected amperometrically. The second method used potassium bromide as electrolyte and the electrode was subjected to dual potential. Bromine, released due to electrolysis at higher potential, was consumed by the allergen protein at lower potential. In the first method, a unique technique was used to microencapsulate the enzyme protease and immobilise it on the surface of the electrode by in‐situ polymerisation to avoid contact with the amino acid oxidase. A total of seven allergens were tested and the results gave a good correlation with the standard protein measurement method. Environmental specimens from indoors, schools and workplaces can be evaluated for the aeroallergens produced by dust mites, animal hairs, cockroach debris, pollens, etc as a means of determining the exposure risk. Copyright © 2005 Society of Chemical Industry     

生物传感器在水污染监测中的应用

综述了生物传感器在水污染监测方面的最新研究进展及应用,主要介绍了生物传感器在生化好氧量(biochemicaloxygendemand-BOD)和水体中污染物浓度测定等方面的应用,并对生物传感器在水污染监测方面的应用前景作了预测和展望。生物传感器可以将传统的BOD测定所需时间大大缩短,并且准确性提高。在对水中各种污染物浓度的测定中应用也非常广泛,具有快速,准确,方便等特点。生物传感器在科研领域和市场上都有极好的发展前景。     

基于生物类脂材料的味觉传感器研究

本文研究了模拟生物味沉构造了人工味觉系统和用于敏感味沉物质的生物类脂材料的敏感特性，选择性及用生物类脂材料构成的多通道电极阵列式味沉传感器。针对基本的五种味沉物质给出有关测试结果以及一些有意义的结论。实践表明，上述方案可用于开发一种产用的新型味沉传感器。     

壳聚糖固定化脲酶生物传感器选择性测定铜离子

基于重金属对脲酶的抑制作用,研制了用于测定铜离子的生物传感器。该生物传感器的制备以壳聚糖为载体,将脲酶固定于pH电极表面。由于壳聚糖对Cu2+的富集,该生物传感器展现出高灵敏度。在样品溶液中加入5 mmol/L NaI,可以消除Hg2+和Ag+的干扰,从而实现Cu2+的选择性检测。在0.005～0.5μg/mL的浓度范围内,脲酶活性的抑制率与Cu2+浓度的对数呈良好的线性响应关系,其检出限为0.002μg/mL。将使用后的生物传感器浸泡于0.5 mmol/L的EDTA溶液再生5 min,被Cu2+抑制的脲酶的活性可以得到恢复。     

DNA电化学生物传感器的研究进展

介绍了DNA电化学生物传感器的组成及原理,综述了近年来单链DNA的固定以及杂交信号的电化学检测方面的研究进展,探讨了纳米材料、纳米技术在DNA电化学生物传感器的制备及应用中发挥的作用,并对DNA电化学生物传感器的发展方向进行了展望.     

葡萄糖的测定方法与应用研究进展

葡萄糖是维持生物体生命、促进生物体生长必须的一种营养成分,葡萄糖的含量测定在发酵、制药、临床诊断等领域具有重要的作用.简要介绍了葡萄糖在生物体中的作用,并详细综述了近年来测定葡萄糖的方法及其在实际应用中的研究进展.最后,对葡萄糖测定方法的的未来发展趋势进行了展望.     

基于螺旋型铂铱合金电极的植入式葡萄糖生物传感器

采用螺旋型铂铱合金电极设计,旨在提高植入式葡萄糖生物传感器的葡萄糖氧化酶担载量并增大工作电极的电化学活性面积.以扫描电镜(SEM)观察聚氨酯(Polyurethane,PU)半透膜的形貌,采用循环伏安法(CV)和计时电流法(I-T)考察PU涂覆厚度、PU含量以及酶含量等参数对传感器电化学性能的影响,结果表明:所制备的螺旋型传感器灵敏度在20 nA/(mmol/L)~30 nA/(mmol/L),可在人体生理条件范围内线性检测(2 mmol/L~30 mmol/L)葡萄糖浓度,并且具有良好的重现性、稳定性和选择性,符合电极长期植入式需求,有望作为今后糖尿病患者血糖连续监测的关键器件.     

心肌细胞电位传感器在海洋生物毒素检测中的研究

目前海洋毒素对人类健康的威胁越加严重,尤其是麻痹性毒素。提出了一种基于细胞电位传感器检测贝类的生物毒性的新方法,采用心肌细胞与微电子加工技术的微阵列芯片（MEA）相结合,构建了新型的心肌细胞电位传感器。通过心肌细胞与MEA芯片的紧密耦合,实现了实时监测心肌细胞电位的变化,输出稳定和一致性好的胞外场电位信号。通过检测海洋中危害较大的石房蛤麻痹性毒素（STX）,分析细胞的信号特征参数,实验结果表明,STX毒素对心肌细胞的电生理活动有明显的抑制作用,对脉冲幅值和脉冲频率有明显的浓度依赖性抑制作用。常规标准的生物毒性检测方法小鼠生物法的检出限为40 g/100 g,而心肌细胞电位传感器可检测的下限为1.004 ng/mL,检测范围为25 nmol/L~1600 nmol/L,通过对比表明该方法具有较好的检出限且检测方法相对简单,易于规范化和标准化。通过进一步的完善,该方法在海洋毒素的快速检测应用方面具有良好的发展前景。     

基于纳米金颗粒放大的电化学传感器用于三聚氰胺的检测

三聚氰胺与胸腺嘧啶（T）之间能够通过三个氢键结合,以富T的DNA探针为识别元件,结合DNA修饰的纳米金颗粒放大技术,以电活性物质钌胺作为信号分子,发展了一种高灵敏检测三聚氰胺的电化学传感器,该传感器具有良好的特异性和灵敏度,检测下限低至0．5nmol／L。     

Electrochemical DNA biosensor for the detection of interaction between di[azino-di(5,6-azafluorene)-κ-NN′]dichlormanganous and DNA

A new Mn(II) complex of MnL₂Cl₂ (L = azino-di(5,6-azafluorene)-κ²-NN′) was synthesized and utilized as an electrochemical indicator for the determination of hepatitis B virus (HBV) based on its interaction with MnL₂Cl₂. The electrochemical behavior of interaction of MnL₂Cl₂ with salmon sperm DNA was investigated on glassy carbon electrode (GCE). In the presence of salmon sperm DNA, the peak current of [MnL₂]²⁺ was decreased and the peak potential was shifted positively without appearance of new peaks. The binding ratio between [MnL₂]²⁺ and salmon sperm DNA was calculated to be 2:1 and the binding constant was 3.72 × 10⁸ mol² L⁻². The extent of hybridization was evaluated on the basis of the difference between signals of [MnL₂]²⁺ with probe DNA before and after hybridization with complementary sequence. Control experiments performed with non-complementary and mismatch sequence demonstrated the good selectivity of the biosensor. With this approach, a sequence of the HBV could be quantified over the range from 1.76 × 10⁻⁸ to 1.07 × 10⁻⁶ mol L⁻¹, with a linear correlation of r = 0.9904 and a detection limit of 6.80 × 10⁻⁹ mol L⁻¹. Additionally, the binding mechanism was preliminarily discussed. The mode of interaction between MnL₂Cl₂ and DNA was found to be primary intercalation binding.