谷氨酸棒状杆菌尿素传感器的研究

基于腺酶催化尿素分解产生氨,以氨气敏电极为基础电极,用含脲酶丰富的谷氨酸棒状杆菌研制成测定尿素的微生物传感器.在30℃、pH8.0、0.1mol/L磷酸盐缓冲液中,该传感器的线性范围为1.1×10^-4～1.4×10^-2mol/L,斜率为51.2mV/decade,检测下限为1.0×10^-5mol/L,寿命可达45d.考察了传感器响应初速和底物浓度之间的关系,测定了微生物膜中脲酶的表观米氏常数K_m及最大响应初速v_m.     

腺苷敏感组织电极的研究

将一种含丰富腺苷脱氨酶的新鲜猪肝组织切片,通过“三明治夹心”法固定于氨气敏电极上,制成对腺苷具有特异响应的生物催化组织膜电极。电极测定腺苷浓度线性范围为1.4×10^-4—1.0×10^-2mol/L,检出限为5.0×10^-5mol/L。并对介质条件,pH影响,选择性以及动力学响应行为进行研究,电极寿命达一个月以上。电极用于合成样品测定,效果满意。     

二茂铁－交联剂修饰的葡萄糖传感器

用牛血清白蛋白-戊二醛交联剂把葡萄糖氧化酶固定在Nafion-二茂铁修饰电极上,最后在电极上修饰一层Nafion膜,制备成葡萄搪传感器,电活性物质如抗坏血酸、尿酸等对葡萄糖的测定无干扰.该传感器的线性范围为5.0×10^-4-1.3×10^-2mol/L,响应时间小于60s.     

甘油三酯酶传感器的研制及应用

将脂肪酶固定在pH玻璃电极上,制成甘油三酯酶传感器.对传感器的制作方法和响应性能进行了研究.在37℃,选择Tris-HCl缓冲溶液(pH 8.5)为测量介质, 所制传感器对甘油三酯的响应线性范围为3.09×10^－6～1.91×10^－3 mol/L,响应斜率为32.7 mV/pC, 响应时间为5～10 min, 使用寿命可达25 d.用研制的传感器测定了人和兔血清中的甘油三酯含量,结果满意.     

测蔗糖复合酶电极的研究

采用酶电极流动注射分析系统(EFIA),由固定化酶膜包括蔗糖转化酶(INV),葡萄糖变旋酶(MuT)及葡萄糖氧化酶(GOD)与氧电极共同组成的复合酶电极用于蔗糖的快速测定。实验确定每张酶膜的最适酶量(Iu比)为lNV：MUT：GOD：72：48：2．4。酶经固定化后,INV与MUT的综合回收活力>42．9％。其最适pH为5．8—6．5。最适温度范围是35—45℃。动态法和稳态法测试的线性范围分别为：5×10^-4—10^-1和10-5—2×10^-3mol／L,响应时间分别<20s和<2 min。实验的重复性良好,变异系数<1．7％。用此酶电极测定以蔗糖为碳源的发酵液中的蔗糖含量,平均回收率达到98％。发酵液中的蔗糖分解产生的葡萄糖对本电极的干扰可通过平行运行的GOD电极来校正。连续使用的寿命至少为120h。比前年报道的14th有了显著的提高。酶膜显示了较好的保存稳定性(30天,保存于4℃蒸馏水中)和一定的抗热性(50℃,30min)。     

H+-Lsfet型青霉素酶传感器

将sos型H^＋－ISFET与戊二醚交联的牛血清蛋白-青霉素酶膜组合成单管输出式青霉素酶－H＋－ISFET传感器的探头(以下简称青霉素－酶FET),并用于测定溶液中的青霉素含量。青霉素－酶FET在0．005mol/L、O．Olmol／L、0．02mol／L磷酸缓冲液中的响应灵敏度分别为11—12mV／m mol／L、7．5—8．0mV／m mol／L以及3．7—4．OmV／m m01／L;响应时间为30s,在0．02mol／L磷酸缓冲液中的标定曲线线性范围为O．5—25mmo】／L’相关系数为O．9976。该青霉素·酶FET在青霉索浓度为10mmol／L的0．01mo1／L磷酸缓冲液中重复测定8次的标准偏差sD为1．67mv,变异系数cv为2．1％;贮存寿命大于4个月,使用寿命在1个月以上(每天测试一次)。     

酵母乙醇脱氢酶电极的研究

从面包酵母中筛选到一株乙醇脱氢酶活力高、杂酶干扰小的菌株。对该菌株进行扩增培养,在72h收获,用此酵母制成测定乙醇浓度的生物电极,该电极测量的线性范围为3．4×10^－5～2．04×10^－3mol/L,r=0．9996,响应时间小于2min,甲醇、叔丁醇、异成醇的干扰分别为1．2％、2.0％、34％,醋酸和葡萄糖不干扰。测定乙醇标准样品的相对标准偏差为1．6％（n=6）,测定白酒发酵样的相对标准偏差为3．1％（n＝6）。     

场效应晶体管型赖氨酸传感器的研究

用自行研制的SOS型氢离子敏场效应晶体管,结合聚乙烯醇膜和赖氨酸脱羧酶膜,研制成场效应晶体管型赖氨酸传感器,其线性响应范围为:0.02％—0.10％,响应灵敏度75±3 mV,响应时间约2 min.传感器寿命达60 d,在pH 6.2的磷酸盐缓冲液中(含10^-3mol/L磷酸吡哆醛),37℃时器件性能最优,同时还考察了硅烷化及膜厚对器件性能的影响.用该传感器初步检测强化赖氨酸饮料的含量,结果与经典的茚三酮显色法基本一致.     

用基因克隆大肠杆菌发光体系测定长链脂肪醛

利用基因克隆大肠杆菌发光体系分别测试了五种长链脂肪醛和脂肪酸。结果表明:可在几分钟内测出癸醛,正辛醛和十二烷醛的极限浓度分别为1×10^-14mol/L、1×10^-12mol/L和1×10^-9mol/L,是一种灵敏、快速的测试方法。     

微生物传感器测定维生素B12的研究

将大肠杆菌(Escherichia coli)215用吸附法固定于醋酸纤维素膜上,与氧电极配合组成微生物电极,建立了对维生紊B₁₂的快速测定系统。测定浓度范围5×10^-6mg—2．5×10^-5mg／ml;测定温度范围在28—39℃;最适Ph为6．7—7．8,测定一个样品所需时间为2h,比常用的生物学测定方法所需时间缩短10倍以上。该系统对维生素B₁₂重复测定的相对误差为±3％。固定化菌体在－25℃保存25天后再进行测定,应答电流不低于初始值的92%。     

瞬时受体电位通道研究进展

瞬时受体电位通道(TRP channels)是位于细胞膜上的一类重要的阳离子通道超家族.根据氨基酸序列的同源性,将已发现的28种哺乳动物,TRP通道分为:TRPC、TRPV、TRPM、TRPA、TRPP和TRPML 6个亚家族.所有的TRP通道都具有6次跨膜结构域.不同的TRP通道对钙离子和钠离子选择性不同.TRP通道分布广泛,调节机制各异,通过感受细胞内外环境的各种刺激,参与痛温觉、机械感觉、味觉的发生和维持细胞内外环境的离子稳态等众多生命活动.     

A new peptidyl fluorescent chemosensors for the selective detection of mercury ions based on tetrapeptide

A novel peptidyl chemosensor (PySO₂-His-Gly-Gly-Lys(PySO₂)-NH₂, 1) was synthesized by incorporation of two pyrene (Py) fluorophores into the tetrapeptide using sulfonamide group. Compound 1 exhibited selective fluorescence response towards Hg(II) over the other metal ions in aqueous buffered solutions. Furthermore, 1 with the potent binding affinity (K_d = 120 nM) for Hg(II) detected Hg(II) without interference of other metal ions such as Ag(I), Cu(II), Cd(II), and Pb(II). The binding mode of 1 with Hg(II) was investigated by UV absorbance spectroscopy, ¹H NMR titration experiment, and pH titration experiment. The addition of Hg(II) induced a significant decrease in both excimer and monomer emissions of the pyrene fluorescence. Hg(II) interacted with the sulfonamide groups and the imidazole group of His in the peptidyl chemosensor and then two pyrene fluorophores were close to each other in the peptide. The decrease of both excimer and monomer emission was mainly due to the excimer/monomer emission change by dimerization of two pyrene fluorophores and a quenching effect of Hg(II).     

DNA生物传感器及其研究进展

就ＤＮＡ生物传感器的工作原理,分类、ＤＮＡ探针的固化方法,以及电化学ＤＮＡ生物传感器、光学ＤＮＡ生物传感器及压电ＤＮＡ生物传感器的研究进展、优缺点和发展趋势加以介绍。     

Cataluminescence‐based sensors: principle,instrument and application

The cataluminescence (CTL)‐based sensor is a new promising type of chemical transducer, and has attracted much attention of researchers for its potential versatile applications in public safety, emission control and environmental protection. In this review, we briefly introduce the development history of CTL‐based sensors and summarize existing explanations of the CTL reaction mechanism as well as three research strategies for mechanism the CTL mechanism. In the following, all the function units of a typical CTL‐based sensor system are described and the investigation of the sensor materials. CTL‐based sensor arrays, are discussed in detail. We classify the recent novel hyphenated techniques based on CTL coupled to other analysis techniques into the preconcentration‐CTL hyphenated technique, nebulization‐CTL hyphenated technique, plasma‐assisted CTL technique and tandem CTL technique according to the type of analysis combined with CTL and provide a detailed account of novel hyphenated techniques. Owing to the appearance of these novel techniques, the application range of CTL has been expanded as well as the sensitivity and selectivity of CTL system has been greatly improved. Finally, the applications of CTL‐based sensor and sensor arrays in the last several years are classified and summarized. Copyright © 2014 John Wiley & Sons, Ltd.     

用菌紫质薄膜传感器进行图像边缘检测的研究

应用菌紫质人工沉淀膜所具有的与动物视网膜类似的微分光电响应特性,以该人工膜为传感器构建了一个可检测图像边缘的原理系统,并成功地检测到了简单图像的边缘。本文的结果除进一步说明了菌紫质分子在图像技术中的应用前途外,还说明了这种分子在视觉功能模拟和人工视觉等方面的良好应用前景 。     

A wearable solution for accurate step detection based on the direct measurement of the inter-foot distance

Accurate step detection is crucial for the estimation of gait spatio-temporal parameters. Although several step detection methods based on the use of inertial measurement units (IMUs) have been successfully proposed, they may not perform adequately when the foot is dragged while walking, when walking aids are used, or when walking at low speed. The aim of this study was to test an original step-detection method, the inter-foot distance step counter (IFOD), based on the direct measurement of the distance between feet. Gait data were recorded using a wearable prototype system (SWING^2DS), which integrates an IMU and two time-of-flight distance sensors (DSs). The system was attached to the medial side of the right foot with one DS positioned close to the forefoot (FORE_DS) and the other close to the rearfoot (REAR_DS). Sixteen healthy adults were asked to walk over ground for two minutes along a loop, including both rectilinear and curvilinear portions, during two experimental sessions. The accuracy of the IFOD step counter was assessed using a stereo-photogrammetric system as gold standard. The best performance was obtained for REAR_DS with an accuracy higher than 99.8% for the instrumented foot step and 88.8% for the non-instrumented foot step during both rectilinear and curvilinear walks. Key features of the IFOD step counter are that it is possible to detect both right and left steps by instrumenting one foot only and that it does not rely on foot impact dynamics. The IFOD step counter can be combined with existing IMU-based methods for increasing step-detection accuracy.     

Novel enantioselective fluorescent sensors for tartrate anion based on acridinezswsxa

Novel chiral fluorescence sensors L‐1 and D‐1 incorporating N‐Boc‐protected alanine and acridine moieties were synthesized. The recognition ability of the sensors was studied by fluorescence titration, ¹H NMR spectroscopy and density functional theory (DFT) calculations. The sensors exhibited good enantioselective fluorescent sensing ability toward enantiomers of tartrate anion for the selected carboxylate anions and formed 1: 1 complexes by multiple hydrogen bonding interactions.     

A study on exposure to ultraviolet rays during outdoor sports activity

1. 1. Intensities of ultraviolet rays (UV) from every direction and the amount of UV absorbed by each body part was measured in four situations (track, beach, golf course and skiing slope).

2. 2. The intensity of UV was measured by a portable UV meter and the amount of UV absorbed by every body part was measured with a UV irradiation energy measurement label.

3. 3. The intensity of UV was strong from S45° and SE45° in all cases. On snow, the intensity of UV from every direction was stronger than in other situations, it was especially strong in reflection from below and from the north. The UV reflection from the sand was slightly larger than that from mud and grass.

4. 4. The experimental day's weather was fine and occasionally cloudy during golf, beach activity and gate-ball, and clear during skiing.

5. 5. The UV deal of a horizontal plane was 135, 98, 156 and 120 kJ/m²/h at golf, beach activity, gate-ball and skiing, respectively.

6. 6. This study suggests that players should be concerned with the prevention of UV radiation during sporting activity.

A colorimetric sensor array based on natural pigments for the discrimination of saccharides

A colorimetric sensor array based on natural pigments was developed to discriminate between various saccharides. Anthocyanins, pH‐sensitive natural pigments, were extracted from fruits and flowers and used as components of the sensor array. Variation in pH, due to the reaction between saccharides and boronic acids, caused obvious colour changes in the natural pigments. Only by observing the difference map with the naked eye could 11 common saccharides be divided into independent individuals. In conjunction with pattern recognition, the sensor array clearly differentiated between sugar and sugar alcohol with highly accuracy and allowed rapid quantification of different concentrations of maltitol and fructose. This sensor array for saccharides is expected to become a promising alternative tool for food monitoring. The link between anthocyanin and saccharide detection opened a new guiding direction for the application of anthocyanins in foods.     

Dynamic concentration challenges for biosensor characterization

A method and apparatus are described for characterization of the steady state and dynamic response of biosensors. The apparatus produces a steady stream of homogeneously mixed analyte whose concentration can be fixed at discrete values or varied continously. The device is ideally suited for continously operated biosensors, but is also effective for biosensors that operate in discrete sampling modes. The system permits simultaneous testing of several sensors and determination of the accuracy, precision and repeatability of sensor response. The characteristics of this testing apparatus were validated with ferrocyanide and glucose as indicators. As an example of use of the apparatus, concentration ramps were created and used to complement conventional step changes for characterizing an implantable glucose sensor. The ramp rate can be adjusted easily by scaling the apparatus to simulate the rate of concentration change anticipated during actual monitoring situations.