快速检测毒死蜱残留量的酶膜生物传感器研究

毒死蜱是一种当前使用广泛的中等毒性有机磷农药．采用传统方法检测毒死蜱．难以满足现场检测的需要。以戊二醛为交联剂．制备了一种基于乙酰胆碱酯酶的酶膜生物传感器．并将其应用于毒死蜱的检测。考察了不同pH值．戊二醛用量．工作环境温度对传感器工作过程的影响。结果表明．本酶膜传感器可定量检出浓度为1．64～20．52mg／kg的毒死蜱。     

聚吡咯修饰电极测定微囊藻毒素

以微囊藻毒素(MC-LR)为模板,采用循环伏安法在金电极的表面电聚合成聚吡咯膜,制备了MC-LR分子印迹电极。在优化制备条件的基础上,对该传感器的线性范围、使用寿命、选择性等进行了研究。结果表明该传感器对MC-LR具有良好的选择性和灵敏度,在0.05⁰.30μg/mL浓度范围内呈良好的线性关系,其相对误差为3.2%,加标回收率为91.0%0.30μg/mL浓度范围内呈良好的线性关系,其相对误差为3.2%,加标回收率为91.0%¹03%,检出限为0.009 4μg/mL。     

苯酚在预活化聚酰胺膜酪氨酸酶生物传感器上的响应特性

研究苯酚在预活化聚酰胺膜酪氨酸酶生物传感器上的响应特性,适量儿茶酚的存在可加快传感器到达恒态的速度。被固定酶的量、活性及传感器的有效面积等是影响检测灵敏度的主要因素。首次采用预活化聚酰胺膜固定酪氨酸酶,并与浸蜡石墨电极组合成酪氨酸酶生物传感器,在温度２５℃电位－０．２００ＶｖｓＳＣＥ,儿茶酚浓度５×１０（－７）ｍｏｌ／Ｌ,底液０．１ｍｏｌ／Ｌ磷酸盐缓冲溶液ｐＨ６．５０下,采用电流法测定苯酚及水样中的酚。酶膜的制备、替换和贮存极为方便,酶膜贮存５个月未见活性下降,有良好的重现性和线性范围２×１０（－７）－１．２５×１０（－５）ｍｏｌ／Ｌ。     

电沉积ZnO膜光电催化降解4-硝基酚研究

用硝酸锌水溶液作电解质,采用阴极电沉积法在玻碳电极上制备了具有光电化学活性的氧化锌(ZnO)薄膜。以ZnO膜电极为工作电极对4-硝基酚进行了光电催化降解处理,系统研究了外加偏压、4-硝基酚浓度、电解液浓度以及pH值对4-硝基酚在ZnO膜电极上的光电催化降解效果的影响。结果表明:在外加偏压为1.0V,电解液浓度为0.1mol/L,溶液为近中性条件(pH为6.3)时对0.05mmol/L的4-硝基酚2小时的降解效率达到了98.8%。     

基于氧猝灭的有机改性溶胶-凝胶微生物传感器测定BOD的研究

通过有机改性溶胶凝胶PVA包埋方法固定微生物菌株，以氧光化学传感器作为二次传感，制备了响应良好的光化学BOD微生物传感器．在此基础上，考察了微生物传感膜的活化浓度、温度、pH、无机盐及部分金属离子对传感器响应的影响．并对传感器的重现性、储存稳定性和线性范围进行了考察，实验结果表明BOD含量在0—100mg/L浓度范围内与传感器的荧光值成线性关系，传感膜的响应活性保持较好，具有较长的使用寿命和良好的稳定性．     

蔬菜中有机磷农药残留的生物传感器法检测

将乙酰胆碱酯酶(AChE)固定在醋酸纤维膜上,将该膜组装在一支pH玻璃电极敏感膜表面,制成用于测定有机磷农药的电位型生物传感器,优化其制备方法。当溶液中存在有机磷农药,酶的活性受到抑制,酶活性的降低引起pH玻璃电极电位的改变,其改变程度与溶液中农药的浓度大小有关。用本文方法测定了蔬菜中的对硫磷、辛硫磷、氧乐果、敌敌畏,结果满意。     

检测重金属离子的酶膜生物传感器的构建

基于重金属对脲酶的特异性抑制作用,研制了可测定重金属离子的电位型酶膜生物传感器。论文考察了脲酶浓度、戊二醛浓度、温度和固定化时间等因素对电位响应的影响,获得了最佳的酶固定化条件,即酶浓度为0.8mg/mL,戊二醛为2.5%,温度为28℃,固定化时间为2h时酶固定化效果最好。同时还初步研究了该生物传感器的响应性能和再生能力。     

对硫磷分子印迹膜传感器的制备及识别特性

用电聚合的方法在金电极上制备了以对硫磷为模板分子的自组装邻氨基硫酚分子印迹膜传感器.在含有5 mmol/L对硫磷模板分子、5mmol/L四丁基高氯酸铵支持电解质和30 mmol/L邻氨基硫酚的二氯甲烷的聚合液中于-0.3～1.4 V范围内循环伏安扫描30圈即得到邻氨基硫酚印迹聚合膜.结合在印迹膜上的对硫磷模板分子用0.5 mol/L HCl溶液超声20 min洗脱.循环伏安法用于电化学检测.当富集时间为10 min,磷酸盐缓冲溶液的pH=6.8时,在1.0×10-4～5.0×10-7mol/L浓度范围内与对硫磷还原峰电流成良好的线性关系,检测下限为2.0×10～mol/L.用分子印迹膜传感器对实际样品进行分析,回收率为98.0%～104%.印迹膜传感器和非印迹膜传感器对一系列与对硫磷相近似的化合物如甲基对硫磷、对氧磷、辛硫磷、氧乐果、硝基苯及邻、间、对硝基苯酚进行检测,该传感器对对硫磷具有良好的选择性和灵敏度.     

多针-水膜电极电晕放电脱硫研究

采用不锈钢多针作为高压电极系统,水膜为低压电极.负直流高压电源供电,含二氧化硫(SO2)的污染气体从高压电极系统的轴向进入,沿着电晕放电电场从水膜上方通过,在电晕放电等离子体和水吸收共同作用下,生成硫酸使SO2得到脱除.主要研究了放电电压、气体中SO2初始浓度和气体在电极系统的停留时间对脱硫效果的影响,并测试了水中SO32-和SI42-离子浓度,分析SO2脱除机制.结果表明,电晕放电和水吸收对SO2脱除具有很好的协同作用,脱硫效果明显升高,SO2转变生成硫酸量的体积分数提高;脱硫效果随电压增加和停留时间的增加而增加,初始浓度对脱硫效果有影响.当SO2初始浓度(体积分数)为430×10-6,施加电压为14.5 kV,停留时间为7.5 s时,脱硫效率达90%以上.     

检测水中有机磷农药的酶传感器

采用丝网印刷技术制作厚膜型电极,通过交联法将乙酰胆碱酯酶固定在电极上,开发快速检测水中有机磷农药的酶传感器.采用循环伏安法对电极所做的检测结果表明电极彼此间的差异在10%以内,具有较好的一致性.通过在交联剂、酶和底物等方面优化传感器的工作参数,确定了戊二醛、酶和底物的浓度分别为0.2%、0.5 mg/mL和10 mmol/L时,传感器响应最好.在交联固定酶的情况下,根据酶活受到有机磷抑制的原理,采用时间-电流法对特丁硫磷和对硫磷进行了检测.结果表明:这2种有机磷的检测限都可以达到1 ng/mL,线性区间1～10 000ng/mL.在物理吸附固定酶的情况下,采用循环伏安法对特丁硫磷进行了检测.结果表明:采用循环伏安法检测的灵敏度比采用时间-电流法的灵敏度要高.     

Direct electrochemistry of glucose oxidase and biosensing for glucose based on DNA/chitosan film

Glucose oxidase (GOD) is widely used in the glucose biosensor industry. The amperometric biosensors based on directly electron transfer (DET) between an electrode and immobilized GOD are especially promising. In this article, GOD was immobilized with a DNA/chitosan bio-material film on GC electrode, and the DET of GOD on DNA/chitosan was studied. The cyclic voltammetric results indicated that the GOD immobilized in the DNA/chitosan film underwent DET reaction, and the cyclic voltammogram displayed a pair of well-defined redox peaks with a formal potential of ?0.45 V (vs. Ag/AgCl) at pH 5.5. The response showed a surface-controlled electrode process with an electron transfer rate constant of 0.91 sec^?1 determined in the scan rate range from 10 to 100 mV/sec. The GOD immobilized in DNA/chitosan membrane retained its biocatalytic activity and stability. The immobilized GOD could electrocatalyze the reduction of dissolved oxygen and resulted in a great increase of the reduction peak current. Upon the addition of glucose, the reduction peak current decreased, which could be used for glucose detection with a sensitivity of 0.48 μA/(mmol/L), a linear range from 0.04 to 2.28 mmol/L and a detection limit of 0.04 mmol/L at a signal-to-noise ratio of 3. The sensor could exclude the interference of commonly coexisted uricacid and ascorbic acid.     

基于固定化AChE的流动注射型酶传感器研究

以固定化鲅鱼脑组织乙酰胆碱酯酶[acetylcholinesterase,AChE(EC 3.1.1.7)]为识别元件,以pH电极为换能器,构建流动注射型AChE酶传感器.该传感器在以磷酸盐缓冲液为载液的条件下具有良好的重现性(RSD=1.427%,n=10)和敏感性,可实现对有机磷化合物的在线监测;对甲基对硫磷具有线性响应的浓度范围为4.29×10-10^-4.29×10^-8mol·L^-1,最低检测限为1.3×10^-     

Preparation of TiO_2/Ti mesh photoelectrode and properties

ＩｎｔｒｏｄｕｃｔｉｏｎＭｕｃｈｉｎｖｅｓｔｉｇａｔｉｏｎｓｓｈｏｗｅｄｔｈａｔｐｈｏｔｏｃａｔａｌｙｔｉｃｏｘｉｄａｔｉｏｎｏｆＴｉＯ2 ｐｒｏｖｉｄｅｓａｎｅｆｆｅｃｔｉｖｅｔｅｃｈｎｏｌｏｇｉｃａｌｍｅｔｈｏｄｆｏｒｔｈｅｄｅｇｒａｄａｔｉｏｎｏｆｔｈｅｏｒｇａｎｉｃｃｏｎｔａｍｉｎａｎｔｓｉｎｗａｔｅｒ(Ａｎｄｊｅｌｋａ ,2 0 0 0 ;Ｆｕｊｉｓｈｉｍａ ,1972 ;Ｈｉｄａｋａ ,1992 ;Ｋｅｓｓｅｌｍａｎ ,1997) .Ｉｎｏｒｄｅｒｔｏｏｖｅｒｃｏｍｅｔｈｅｓｈｏｒｔｃｏｍｉｎｇｓｔｈａｔｔｈｅｒｅｃｏｖ…     

Preparation of TiO2/Ti mesh photoelectrode and properties

An innovative photoelectrode,TiO2/Ti mesh electrode,was prepared by anodisation.In anodisation,0.5 mol/L H2SO4 was used as electrolytic solution,the current had been constantly 1A from the beginning of the oxidation until reaching a designed voltage.Results showed that the photocatalytic activity of electrode was better when the designed voltage was 160 V.The morphology and the crystalline texture of the TiO2 film on mesh electrode were examined by scanning electronic microseopy and Raman spectruscopy respectively.The examination results indicated that the structure and properties of the film depended on anodisation rate,and the anatase was the dominant component under the eontrolled experimental conditions.Degradation of Rhodamine B in photocatalytic (PC)and photoelectrocatalytic(PEC) reaction was investigated.     

环保型二次锌电极的研究

为了保护环境 ,减小污染 ,节约金属资源 ,十分有必要研究和开发环保型二次锌电极。本文提出了在表面覆盖稀土氢氧化物膜的二次锌电极的新思想 ,首先利用恒电位电解的方法在电极表面成功地覆盖一层均匀致密的稀土氢氧化物膜 ,再用恒电位电解、循环伏安、模拟充放电等实验方法 ,全面考察了稀土氢氧化物膜对锌电极可充性的影响。实验结果表明 :在锌电极表面成膜后 ,可以显著地抑制充电过程中的枝晶生长 ,又在电解液中加入枝晶抑制剂 ( CTMB) ,最后达到了令人满意的效果 ;同时 ,成膜还能有效地缓解锌电极在充放电过程中的容量损失。在整个实验过程中 ,完全去掉了传统的锌电极添加剂——有毒的汞 ,从而为研究和开发实用的环保型二次锌电极提供了一条新的途径     

纳米铂微粒电极催化氧化有机污染物的研究

采用电化学阴极还原-阳极氧化方法制备了纳米铂微粒电极.电极表面的微观结构表征表明,铂微粒在三维网状的氧化钛膜孔道中呈均匀、高度分散状态,且粒径细小,铂微粒充分裸露,使得纳米铂微粒电极活性点多,电催化性能高.采用循环伏安法研究了铂微粒电极对有机小分子代表性物质甲醇的电催化氧化行为.结果表明,在酸性、中性和碱性介质中纳米铂微粒电极对甲醇的电催化氧化性能均明显优于光滑铂片电极,甲醇在纳米铂微粒电极上产生的氧化电流密度比光滑铂片电极高100倍以上.2种铂电极催化氧化降解甲醇、苯酚和甲基橙3种有机物时,纳米铂微粒电极的平均氧化电流效率是光滑铂片电极的数倍,这进一步表明纳米铂微粒电极对有机污染物具有良好的催化氧化降解能力.     

Electrochemical decolorization of dye wastewater by surface-activated boron-doped nanocrystalline diamond electrode

Complex organics contained in dye wastewater are difficult to degrade and often require electrochemical advanced oxidation processes (EAOPs) to treat it. Surface activation of the electrode used in such treatment is an important factor determining the success of the process. The performance of boron-doped nanocrystalline diamond (BD-NCD) film electrode for decolorization of Acid Yellow (AY-36) azo dye with respect to the surface activation by electrochemical polarization was studied. Anodic polarization found to be more suitable as electrode pretreatment compared to cathodic one. After anodic polarization, the originally H-terminated surface of BD-NCD was changed into O-terminated, making it more hydrophilic. Due to the oxidation of surface functional groups and some portion of sp² carbon in the BD-NCD film during anodic polarization, the electrode was successfully being activated showing lower background current, wider potential window and considerably less surface activity compared to the non-polarized one. Consequently, electrooxidation (EO) capability of the anodically-polarized BD-NCD to degrade AY-36 dye was significantly enhanced, capable of nearly total decolorization and chemical oxygen demand (COD) removal even after several times of re-using. The BD-NCD film electrode favored acidic condition for the dye degradation; and the presence of chloride ion in the solution was found to be more advantageous than sulfate active species.     

Acute effects of chlorpyryphos-ethyl and secondary treated effluents on acetylcholinesterase and butyrylcholinesterase activities in Carcinus maenas

The acute effects of commercial formulation of chlorpyrifos-ethyl (Dursban(r)) and the secondary treated industrial/urban effluent (STIUE) exposure on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activities in hepatopancreas and gills of Mediterranean crab Carcinus maenas were investigated. After 2 d of exposure to chlorpyriphos-ethyl, the AChE activity was inhibited in both organs at concentrations of 3.12 and 7.82 μg/L, whereas the BuChE was inhibited only at higher concentration 7.82 μg/L of commercial preparation Dursban(r). The exposure of crabs to Dursban(r) (3.12 μg/L) showed a significant decrement of AChE activity at 24 and 48 h, whereas the BuChE was inhibited only after 24 h and no inhibition for both enzymes was observed after 72 h. Moreover, a significant repression of AChE activity was observed in both organs of C. maenas exposed to 5% of STIUE. Our experiments indicated that the measurement of AChE activity in gills and hepatopancreas of C. meanas would be useful biomarker of organophosphorous (OP) and of neurotoxic effects of STIUE in Tunisia.     

TiO_2/Ti薄膜电极制备和光电催化降解罗丹明B的研究

以TA1钛合金为原料采用阳极氧化法制备新型薄膜电极 -TiO2 Ti电极 ,运用X射线衍射法、扫描电镜对电极表面膜的粒径、物相进行了表征。结果表明 ,控制反应条件 ,薄膜中二氧化钛晶型以锐钛矿型为主 ,粒径 45～ 5 0nm ,将其应用于光催化氧化水中的罗丹明B ,该电极对其降解有很好的光催化活性 ,同时 ,外加一定的偏压可以提高光催化氧化的效率