大肠杆菌BOD微生物传感器的研究

本研究以性能优良的大肠杆菌作为敏感材料，采用聚乙烯醇包埋方法获得了测量范围广，稳定性好，灵敏度高的BOD微生物传感器，实验结果表明，传感器在温度30℃，pH为7．0条件下，对GGA标准溶液的线性响应范围为0－500mg/L，其线性相关系数达到0．99以上，响应时间在12min内，测定结果与标准法测定值具有良好的相关性，连续稳定工作寿命在6个月以上。     

生物传感器快速测定BOD的研究

介绍了一种以一株耐高渗透压的酵母菌种作为敏感材料制成的生物传感器、采用稳态吸速率法进行生化需氧量（BOD）的快速测定的方法。该方法与广为采用的5d生化需氧量标准稀释测定法有良好的相关性,线性范围为0－200mg／L,可在15min内完成一个样品BOD的测定,测量恢复时间为30min。敏感材料的生物活性与测定样品中有机物的种类有密切关系。固定化酵母具有较好的稳定性,可连续使用一个月以上。     

生物传感器快速测定BOD仪的开发

对生物传感器快速测定BOD的试验装置与测定方式进行了改进,改进后的测定系统具有良好的重现性和准确度。同时确定了最佳测定条件为温度30℃,PH5．0,固定化细胞15g。     

我国致力于氯化镓紫外探测器研发

我国在氮化镓紫外探测器的研究上，单元探测器的系列关键技术取得了突破，研制成功了氮化镓紫外探测器。探测器的主要性能指标达到了较高水平，其中探测器的光电流响应率一般均达到0．10A／W以上，探测器的结构采用pin或pn结型或Schottky结型光电二极管方式，直径0．5mm的pn结的零偏压电阻值一般在100MΩ以上，可以用作各类紫外产品的传感器探头。     

封装厚度和位置对PVDF压电薄膜传感器电荷量的影响

近年来，聚偏氟乙烯(PVDF)压电薄膜传感器因可无源供电而得到广泛研究。PVDF压电薄膜传感器在使用时会进行封装，聚对苯二甲酸乙二醇酯(PET)薄膜是常用的封装材料。为了探究封装材料厚度和封装位置对传感器响应电荷量的影响，设计了6种封装厚度和封装位置不同的传感器，在不同频率下测定其产生的电荷量。结果表明：在0～20Hz和80～100Hz范围内，选择100μm或125μm的封装厚度可得到更多的电荷量；封装位置同样会影响电荷量的产生。同时分析了封装位置影响传感器产生电荷的机理。     

压阻式微悬臂梁免疫传感器检测小分子T-2毒素及动力学分析

摘要：为了探索压阻式微悬臂梁免疫传感器用于小分子T-2毒素的检测效果及其动力学响应规律．基于生物素一亲和素放大系统构建了一种操作简单、快速灵敏的非标记传感器。该传感器对T-2毒素的检测限为4txg／L（S／N≥3）,检测的线性范围为4—60μg,L,线性回归方程为AUe=0．447C＋1．315（n=5,R=0．983,p〈0．001）。传感器具有很好的特异性和重现性,能满足河水、土壤、食品等实际模拟样品的检测要求。基于配体一受体动力学和吸附动力学创建了两种压阻式微悬臂梁免疫传感器检测小分子T-2毒素的响应动力学模型．对T-2毒素实际检测数据进行拟合分析。结果表明：创建的这两种模型均能较好地拟合T-2毒素实际检测数据,相关系数R值在0．9689以上（p〈0．001）。基于配体一受体特异结合动力学模型由于考虑了敏感膜与靶分子间的特异相互作用,对T-2毒素实际检测数据的拟合效果更佳。相关系数R值在0．9703以上（p〈0．001）,能更好的反映压阻式微悬臂梁免疫传感器检测小分子T-2毒素的响应特点和规律;并且能求出更有意义的平衡响应电压（△Ue）、响应时间（tO）等参数．且根据曲线拟舍方程求出的△Ue、t0均与实测值非常接近．     

藻类水体中BOD5监测方法的探讨

随着全球富营养化问题的日趋严重，藻类早己成为水源与供水系统中重要的水质指标，藻类水体的BOD5测定结果往往偏高，本文通过分析藻类水体中BOD5偏亭引起的原因，通过謇验验呼了消除藻类干扰BOD5的监测方法。     

纳米颗粒对葡萄糖生物传感器性能影响的研究

制备了纳米金颗粒和纳米铜颗粒，分别用以修饰葡萄糖生物传感器，并选用丝网印刷金电极测试研究了纳米颗粒对葡萄糖生物传感器性能的影响。结果表明：纳米铜颗粒不能增强葡萄糖生物传感器的响应电流，并且延长了其响应时间；纳米金颗粒增强了葡萄糖生物传感器的响应电流，缩短了其响应时间，提高了其抗干扰性，但不能拓宽其检测的线性范围，并且响应电流受工作电压的影响较大；随着工作电压的下降，响应电流迅速下降，与未修饰葡萄糖生物传感器响应电流下降趋势一致。     

TELEDYNE 310型微量氧分析仪进样气路系统的改进

TELEDYNE 310型微量分析仪是美国TELEDYNE公司研制开发的一种便携式微量氧分析仪，使用电化学传感器-燃料电池检测器来完成气体中微量氧含量的测定。该分析仪何种小，携带方便，操作简便，响应速度快，量程范围宽，示值稳定，可用于多种气体中氧含量的测定，是较为理想的微量氧测定仪器。     

基于碳纳米管无纺布的葡萄糖氧化酶生物传感器

以化学气相沉积法直接合成的碳纳米管无纺布作为电极材料,采用简单的包埋法,通过葡萄糖氧化酶和聚乙烯醇的水溶液固定葡萄糖氧化酶制备生物传感器。利用SEM、TEM和BET表征碳纳米管无纺布的内部形貌及孔径分布;利用双电测四探针测试仪和万用表测定碳纳米管无纺布的导电性能;利用拉伸仪测试碳纳米管无纺布的力学性能;利用电化学工作站测定生物传感器的电化学行为及电流响应信号。结果显示传感器的响应电流随葡萄糖浓度的增加呈线性变化,线性范围为2.5 mmol/L~30 mmol/L,检出限为2.5 mmol/L,响应时间约10 s,经硝酸处理可进一步提高传感器的响应电流。基于碳纳米管无纺布的葡萄糖氧化酶生物传感器可实现对葡萄糖的有效检测。     

Development of a rapid ferricyanide mediated assay for biochemical oxygen demand using a mixed microbial consortium

Ferricyanide-mediated (FM) microbial reactions were used for the rapid determination of the biochemical oxygen demand (BOD) of a range of synthetic and real wastewater samples. Four single-species microbial seeds and a synthetically prepared microbial consortium were compared. In all cases, the microbial consortium exhibited a greater extent and rate of biodegradation compared to the individual microbial seeds. Markedly improved correlation to the standard BOD5 method was also noted for the microbial consortium (compared to the single-species seeds). A linear dynamic range up to 200 mg BOD5 L(-1) was observed, which is considerably greater than the linear range of the standard BOD5 assay and most other rapid BOD assays reported. In addition, biodegradation efficiencies comparable to the 5-day BOD5 assay (and much greater than other rapid BOD assays) were observed in 3 h. A highly significant correlation (R = 0.935, p = 0.000, n = 30) between the FM-BOD method and the standard BOD5 method was found for a wide diversity of real wastewater samples. The results indicate that the FM-BOD assay is a promising, rapid, alternative to the standard 5-day BOD5 assay.     

Multimicrobial sensor using microstructured three-dimensional electrodes based on silicon technology

Two microbial strains with different substrate spectra were immobilized separately within a single biosensor chip featuring four individually addressable platinum electrodes. These were sputtered onto the inner surface of four isolated pyramidal cavities ("containments") micromachined on a silicon wafer. The biosensor chip was integrated into a flow-through system to measure the oxygen consumption of the immobilized microorganisms in the presence of assimilable analytes. As a model system, a yeast for the determination of biochemical oxygen demand (BOD) and a strain capable of degrading polycyclic aromatic hydrocarbons (PAH) were chosen. It was shown that the simple and mass-producible containment sensor exhibits good performance data: lower detection limit 0.1 mg/L naphthalene and 1 mg/L sensor-BOD; calibration range up to 30 mg/L; precision 3-6%; response time 2-3 min; service life up to 40 days; shelf life at 4 degrees C 6 months. The versatility of the multimicrobial sensor was demonstrated by measuring ordinary municipal wastewater samples as well as various aqueous samples contaminated with PAH. The concept of a multimicrobial sensor not only enlarges the substrate spectrum for sum parameters such as BOD but leads to additional information which allows for a more differentiated and immediate knowledge of sample composition. Using chemometrical data analysis, the multimicrobial sensor lays a foundation for developing an "electronic tongue".     

Zinc oxide nanoparticle based optical fiber humidity sensor having linear response throughout a large dynamic range

The main objective of the present work is to develop an optical fiber relative humidity (RH) sensor having a linear response throughout over the widest possible dynamic range. We report an optical fiber RH sensor based on the evanescent wave absorption spectroscopy that fulfills this objective. The fiber sensor employs a specific nanoparticle (zinc oxide) doped sol-gel nanostructured sensing film of optimum thickness, synthesized over a short length of a centrally decladded straight and uniform optical fiber. A detailed experimental investigation is carried out to analyze the sensor response/characteristics. Fiber sensor response is observed to be linear throughout the dynamic range as wide as 4% to 96% RH. The observed linear sensitivity for the fiber sensor is 0.0012?RH(-1). The average response time of the reported sensor is observed to be as short as 0.06?s during the humidification. In addition, the sensor exhibited a very good degree of reversibility and extremely high reliability as well as repeatability.     

Nafion film/K(+)-exchanged glass optical waveguide sensor for BTX detection

An optical waveguide (OWG) sensor for the detection of BTX gases is reported. The highly sensitive element of this sensor was made by coating the copper Nafion film over a single-mode potassium ion exchanged glass OWG. We used the OWG sensor to detect toluene gas as a typical example BTX gas. The sensor exhibits a linear response to toluene in the range of 0.25-4250 ppm with response and recovery times less than 25 s. The sensor has a short response time, high sensitivity, and good reversibility.     

Amperometric uric acid biosensors fabricated of various types of uricase enzymes

Preparation process of an enzyme-based bipotentiostatic amperometric uric acid sensor has been investigated. The suitability of three different Uricase (EC 1.7.3.3) enzymes (from porcine liver, Candida Utilis, Bacillus Fastidiosus) is described in this paper. The sensor fabricated of Uricase from Candida Utilis showed a linear response to uric acid in the 0-0.9 mM concentration range and the response current range was 0-3.3 /spl mu/A. The sensor fabricated of Uricase from Bacillus Fastidiosus has been saturated at 0.72 mM and the response was not linear above 0.24 mM. The response current range was 0-0.9 /spl mu/A. The sensor fabricated of Uricase from porcine liver has not given detectable electrical signal due to its very low specific activity. The substrate was prepared by screen printing on sintered alumina ceramic sheets using pastes of Au or Pd-Pt as working (W) and counter (C) and Pt-Ag as a reference (R) electrode. Galvanostatic electrocopolymerization of dodecyl sulfate doped poly-N-methyl-pyrrole (pNMPy) layer was used for enzyme immobilization. The layout of the sensor consists of four electrode surfaces (W/sub 1/, W/sub 2/, R, and C). By the bipotentiostatic technique, the two working electrodes (with and without the enzyme) are identically prepared and polarized, while the currents in the two circuits are measured simultaneously; thus, the current of the W/sub 2/-C circuit (I/sub 2/) can be substracted as a nonspecific background noise. The nonspecific oxidation of uric acid on the poly-N-methyl-pyrrole layer at 0.2 V has been demonstrated in oxygen bubbled buffer solution.     

Sol-gel-based, planar waveguide sensor for gaseous iodine

A novel sensor for gaseous iodine has been developed using a combination of sol-gel processing and planar integrated optical waveguiding technologies. The sensing principle is based on the detection of a charge transfer complex formed between iodine and phenyl groups that have been incorporated into a porous, methylated glass film. The glass film was prepared from siloxane precursors by the sol-gel method. Sensors were fabricated by coating the film over a single-mode planar waveguide. Light was coupled into and out of the laminate structure using integral grating couplers, and formation of the charge transfer complex was monitored as attenuated total reflection of the guided wave. The sensor exhibits a linear response to I(2) in the range of 100 ppb to 15 ppm with response and recovery times less than 15 s. The response is selective to 4 ppm iodine in the presence of 10 ppm chlorine and is stable for at least 3 months.     

阵列光电传感器的非线性校正

阵列光电传感器在接近饱和时表现出非线性,但是可以通过阵列传感器的线性区的系数外推得到修正,而且只需在一个波长位置测得曝光量与A/D转换值的响应曲线,将能够推广到任意波长位置。为此,利用最小二乘法进行多项式拟合和软件的非线性校正,在同等硬件配置的条件下,增加了线阵传感器的线性区,延拓了传感器的动态范围。在整个动态范围内,系统测量误差可以减少到±2%。此非线性校正方法也非常适用于光电阵列传感器的光谱仪生产厂的强度定标校正。     

A glucose sensor made of an enzymatic clay-modified electrode and methyl viologen mediator

A novel glucose sensor has been contrived by immobilizing glucose oxidase between two nontronite clay coatings on glassy carbon electrode with methyl viologen as mediator. The sandwich configuration proved to be very effective in the determination of glucose. The response of the glucose sensor was determined by measuring cyclic voltammetric peak current values under aerobic solution conditions. The effects of the amount of enzyme immobilized, the operating pH, and the common interferences on the response of the glucose sensor were studied. The detection limit was 5 μM, with a linear range extending to about 6 mM, giving a dynamic range of over 3 orders of magnitude for 0.1 mM methyl viologen. When stored in pH 7 phosphate buffer at 4 °C, the sensor shows almost no change in performance after operating for at least 2 months. A mechanism for the operation of the glucose sensor is also proposed.     

Carbon dioxide gas sensor based on ionic liquid-induced electrochemiluminescence

Electrochemiluminescence of the luminol-O(2) system in an electrolyte-free N,N-dimethylformamide (DMF)-dipropylamine (DPA) cosolution is induced by the formation of a carbamate ionic liquid (IL) from the reaction between CO(2) and DPA, on the basis of which a facile ECL sensor for measuring atmospheric CO(2) has been developed. This ECL sensing method shows several advantages in the detection of CO(2), such as high safety, high selectivity, wide linear response range, and good sensitivity. The gas sensor was found to have a linear response range from 100 ppm to 100 v/v% and a detection limit of 80 ppm (at signal-to-noise ratio of 3). This is the first reported IL-induced ECL sensor for a gas, thus the principle of this type of sensor and the IL-induced ECL mechanism have been demonstrated in detail.     

Biomolecular sensors for neurotransmitter determination: electrochemical immobilization of glutamate oxidase at microelectrodes in a poly(o-phenylenediamine) film

The adsorption of glutamate oxidase onto 25 Μm and 10 Μm platinum microelectrodes followed by immobilization in an electrochemically polymerized non-conducting polymer, poly(o-phenylenediamine), is described as a method of fabricating an enzyme electrode for the amperometric determination of glutamate. The response of the enzyme electrodes were found to be highly reproducible with a linear dynamic range upto approximately 15 mmol dm^?3. The response of the 25 Μm and 10 Μm enzyme electrodes to glutamate were analysed using an established kinetic model and the potential application of the sensor for the study of neurotransmitter dynamics was investigated. The sensor was stable over a period of 30 days and the polymeric film was found to reduce interference from the electroactive compounds, uric acid and ascorbic acid.