丙烯腈-丙烯酸共聚物多孔膜的硫化物传感器

采用自由基聚合方法在金电极表面合成丙烯腈-丙烯酸的共聚物多孔膜并用作固定酶的载体.再通过戊二醛将辣根过氧化物酶交联固定在丙烯腈-丙烯酸的共聚物多孔膜上制得过氧化氢生物传感器.硫化物抑制酶的活性使还原电流减小,根据电流域小的程度实现了对硫化物的测定.丙烯腈-丙烯酸共聚物多孔膜具有大的表面积和高的吸附能力.有利于改进传感器的检测下限.实验结果表明:将辣根过氧化物酶固定在丙烯腈-丙烯酸的共聚物多孔膜金电极上,作为一种检测硫化物的抑制型传感器,分析响应性能良好.     

酶生物传感器固定化酶载体的研究

选用具有生物亲合性的蛋壳膜作载体,采用戊二醛为交联剂的交联法对葡萄糖氧化酶进行固定化,与用蛋壳膜作支撑体的溶胶-凝胶法固定化酶作比较.利用基于氧电极的葡萄糖氧化酶传感器模型,着重研究了不同条件下固定化酶的活性,发现蛋壳膜法固定化葡萄糖氧化酶的活性较高,证明了蛋壳膜是一种很好的固定化酶的载体材料.     

苯乙烯-马来酸酐交替共聚物钠盐/聚苯乙烯磺酸钠复合物的湿敏特性

以苯乙烯-马来酸酐交替共聚物钠盐(NaSMA)与聚苯乙烯磺酸钠(NaPSS)复合物为湿敏材料,在叉指金电极上浸涂成膜制备了电阻型湿度传感器,考察了NaSMA和NaPSS浓度对复合湿度传感器响应特性的影响.研究表明,加入NaPSS可降低传感器在低湿下电阻,同时提高传感器的高湿灵敏度.在最佳条件下,当环境湿度从33%RH增...     

共价固定卟啉作为荧光载体的pH光化学传感器的研究

合成了末端带双键的卟啉荧光载体,将其与甲基丙烯酸羟乙酯、丙烯酰胺等在紫外光照射下,共聚于经预处理过的玻片上,制成共价固定卟啉荧光载体的光化学传感器.该传感器重现性好,寿命长.实验发现,该传感器可用于pH2.00～6.00范围内测定溶液的pH值,且常见的金属离子如Hg2 、Pb2 、Cd2 、Fe3 、Cu2 等不干扰pH的测定.     

声表面波醋酸气体传感器的气敏特性

本文研究了声表面波醋酸气体传感器的气敏特性。选用了复合膜材料，性能稳定响应时间２０秒，灵敏度高，膜材料受溶剂的干扰小，选择性好。     

石英传感器刻蚀工艺研究

化学刻蚀是石英传感器制造中常用的工艺方法。化学刻蚀必须解决腐蚀液和保护膜两大问题，腐蚀液浓度，温度，石英材料的质量，抛光质量等对传感器表质量，尺寸精度，性能有影响。     

溶解氧测量传感器及其应用

介绍了溶解氧测量中双电极，三电极有膜型传感器的特点及新型无膜型Ｄ．Ｏ传感器的结构与应用。     

TiO2薄膜氧敏特性研究

金属氧化物随氧分压不同，有改变电导率这一性质而被广泛地用来制作氧敏传感器，传统的传感器大多是体材料或厚膜材料，工作时需加高温。本文描述的是ＴｉＯ２薄膜材料与Ｐｔ薄膜形成的肖特基势垒高度随氧分压不同而改变的氧敏现象，测定了该肖特基二极管的氧敏特性，并讨论了它的敏感机理。     

高分子膜及其在光纤气体传感器中的应用

高分子膜具有制备简单、性能稳定以及与指示剂相容性好等特点,是光纤气体传感器中固定指示剂的优良基质材料。简单介绍了用于光纤气体传感器的高分子膜的特点、制备方法及其性能影响因素,综述了近年来基于高分子膜的光纤气体传感器的研究进展。     

一次性葡萄糖传感器中水溶性高分子材料的选择

对多种水溶性高分子材料稳定性、水溶性、成膜性及制备酶电极的电流响应性能等方面进行了系统的研究.实验表明使用1%的羧甲基纤维素钠(CMC)作为一次性葡萄糖传感器的包酶载体,固定化酶膜效果好,制得的葡萄糖传感器电流响应呈线性,灵敏度为111 nA/(mmol/L).     

基于金属—有机骨架材料的C反应蛋白传感器研制

在常温下合成了Au纳米颗粒负载的超纳米结构金属有机骨架化合物(Au NPs/SNHKUST—1),并以其为标记材料标记C反应蛋白抗体.同时合成了中空状石墨烯纳米材料和Au纳米颗粒作为固定基质,制备了夹心型的C反应蛋白免疫传感器.通过检测标记物对H2 O2还原反应的催化电流,实现了对C反应蛋白的定量测定.传感器在C反应蛋白浓度为0.2~200 ng/mL的范围内线性良好的,线性相关系数R2=0.9947,检测下限为0.05 ng/mL,为C反应蛋白测定提供了一种新的简单快速的检测方法.     

Electrochemical immunosensor for salbutamol detection based on CS-Fe3O4-PAMAM-GNPs nanocomposites and HRP-MWCNTs-Ab bioconjugates for signal amplification

An ultrasensitive electrochemical immunosensor based on chitosan-iron oxide-poly(amino-amine) dendrimers-gold nanoparticles (CS-Fe₃O₄-PAMAM-GNPs) nanocomposites and horseradish peroxidase-multiwall carbon nanotubes-antibody (HRP-MWCNTs-Ab) bioconjugates was developed for the detection of salbutamol (SAL). CS-Fe₃O₄-PAMAM-GNPs nanocomposites as immobilization matrix were used to enhance the electroactivity and stability of the electrode. HRP-MWCNTs-Ab bioconjugates as label were used to improve catalytic activity for hydrogen reduction of the electrode. Under the optimized conditions, a calibration plot for SAL was obtained with a linear range between 0.11 ng/mL and 1061 ng/mL (r = 0.9984). The detection limit was 0.06 ng/mL. The immunosensor was examined in real samples for the analysis of SAL.     

Highly sensitive label-free immunosensor for ochratoxin A based on functionalized magnetic nanoparticles and EIS/SPR detection

A label-free immunosensor for the detection of ochratoxin A (OTA) based on use of magnetic nanoparticles (MNPs) was developed. A gold electrode was modified using bovine serum albumin conjugate with a glutaraldehyde-thiolamine linker, creating a layer that prevents non-specific binding of OTA on gold. The OTA antibodies were attached to MNPs using the carbodiimide chemistry and afterwards were immobilized on the modified gold electrode using a strong magnetic field. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and surface plasmon resonance (SPR) were used to characterize each step in immunosensor development. The impedance variation due to the specific antibody-OTA interaction was correlated with the OTA concentration in the samples. The increase in electron-transfer resistance values was proportional to the concentration of OTA on a linear range between 0.01 and 5 ng/mL, with a detection limit of 0.01 ng/mL. SPR measurements showed a larger response range (1-50 ng/mL) with a detection limit of 0.94 ng/mL. Analytical results were in accordance with standard ELISA test kit.     

基于抗体包被纳米金和铜配合物共固定修饰电极的癌胚抗原安培免疫传感器研究

研制了基于抗体包被化学镀纳米金(AuNPs)和[Cu(bpy)2(ONO)]NO3配合物(CuL)共固定修饰玻碳电极(GCE)的安培免疫传感器,并用于血清中癌胚抗原(CEA)的检测。首先将GCE电极表面氧化形成羧基,进而键合上乙二胺。将此胺化电极浸泡在CuL和化学镀金溶液后,CuL可通过π-π堆积作用吸附到GCE表面,并在电极表面还原成30~50nm的纳米金层(GCE|CuL/AuNPs)。将上述电极浸泡在CEA抗体(anti CEA)溶液中,利用AuNPs固定anti CEA,并通过辣根过氧化物酶(HRP)封闭剩余的AuNPs位点,由此构建了一类快速检测CEA的无试剂安培免疫传感器(GCE|CuL-AuNPs/anti CEA-HRP)。其中CuL作为电子媒介体对过氧化脲(CP)有催化还原作用,而且HRP可增强这种作用。当该传感器在37℃下,含CEA的pH6.5PBS溶液中温育30min后,随着温育液中CEA浓度的增加,电极表面形成的免疫复合物也增加,导致CuL对CP的催化电流下降。电流下降百分比1%与CEA浓度在0.1~80ng/mL之间成线性关系,检测限为0.052ng/mL(3σ)。由于采用化学镀法可...     

Development of amperometric immunoassays (AIAs) for calpastatin and μ-calpain with possible applications in the biomedical field

Due to the involvement of calpains and calpastatin in the pathology of several diseases, it is important to create an analytical tool for their accurate and sensitive measurements. In this work, an amperometric immunoassay (AIA) was developed and optimized for quantification of two key proteins from the calpain proteolytic system. The detection is based on the measurement of a steady-state current on screen printed electrodes due to the reduction of the enzymatic product resulting from specific immunoassays, where the measured current is proportional to the concentration of the target analyte. The optimized assays with dynamic ranges from 0.09 to 6 ng/mL for calpastatin and 0.04 to 5 μg/mL for calpain, offer simplicity, sensitivity and possibility for miniaturization.     

Direct-binding quartz crystal microbalance immunosensor to detect carp metallothionein

Metallothionein (MT) is a valuable biomarker against xenobiotic heavy metal contamination in organs and blood of fish. In this study, MT was induced in carp blood by cadmium injection and was purified to homogeneity by DEAE-cellulose ion exchange column chromatography to be used dually as a standard and immunogen. A sensitive detection on carp MT was then followed using a batch-type direct-binding quartz crystal microbalance immunosensor system installed with a well cell. Among antibody immobilization methods tested, two methods that were carried out via a heterobifunctional thiolation cross-linker, and via the cross-linker and protein G showed their respective advantages in simplicity and sensitivity. When analyzed using the immunosensor for carp MT in the concentration range of 50-4000 ng/mL, the limit of detection around 250 ng/mL was obtained. Based on its reasonable sensitivity and real-time presentation for the sensor signal, the immunosensor of this study was presumed as a screening tool to monitor possible heavy metal contamination in a fish farm and imported fish.     

基于囊状银钯铂合金的无标记型癌胚抗原免疫传感器的研制

该文将所合成的中空囊状银钯铂合金和壳聚糖（CHIT）修饰于玻碳电极（GCE）表面,利用中空囊状银钯铂合金比表面积大、反应活性位点多、导电能力良好、催化性能优异和吸附能力强等优点将癌胚抗原的抗体（anti-CEA）固定到电极表面,从而制得高灵敏的无标记型癌胚抗原（CEA）免疫传感器。当抗体与抗原发生免疫反应形成复合物时,会降低银钯铂合金的电催化活性并增加传质阻力。采用示差脉冲伏安法（DPV）检测电化学探针铁氰化钾的响应电流信号的减小程度,实现对CEA的检测。实验考察了电极表面的电化学行为,并对免疫传感器的性能进行了研究。在最优的实验条件下检测癌胚抗原的线性范围为0.5-80.0 ng/mL,线性相关系数为0.989 0,检测下限为0.17 ng/mL。     

Sensitive electrochemical immunosensor for the detection of cancer biomarker using quantum dot functionalized graphene sheets as labels

Quantum dot (QD) functionalized graphene sheets (GS) were prepared and used as labels for the preparation of sandwich-type electrochemical immunosensors for the detection of a cancer biomarker (i.e., prostate specific antigen (PSA)). The primary anti-PSA antibody was also immobilized onto the GS. The immunosensor displayed a wide range of linear response (0.005-10 ng/mL), low detection limit (3 pg/mL), and good reproducibility, selectivity and stability. The immunosensor was used to detect PSA in patient serum samples with satisfactory results. Thus, this unique immunosensor may provide many applications in clinical diagnosis.     

Electrochemical detection of TNT with in-line pre-concentration using imprinted diethylbenzene-bridged periodic mesoporous organosilicas

We examined the adsorption and release of TNT using diethylbenzene-bridged (DEB) periodic mesoporous organosilica sorbents under varying conditions. The sorbents were applied for in-line target pre-concentration in conjunction with an electrochemical flow cell containing a glassy carbon electrode. Square wave voltammetry was employed for TNT detection. TNT sample volumes between 2 and 480 mL at concentrations ranging from 0.5 to 500 ppb were passed through the DEB sorbents (imprinted or not imprinted for TNT) at pH 6 (sodium acetate) or at pH 7.4 (PBS). Release of target was accomplished using solvent mixtures of methanol/water with sodium acetate as electrolyte or acetonitrile/water with PBS components as electrolyte. Under these conditions, the TNT was released in <200 μL of the solvent mixture, and pre-concentration factors of >3000 can be achieved when using large volumes of trace TNT samples. When sample volumes of 2 mL were utilized, the sensing system gave a linear response between 20 and 500 ppb with an estimated limit of detection of 13 ppb. When pre-concentrating 480 mL of sample in either buffered solution or seawater, detection of 0.5 ppb TNT was achieved with a signal to noise ratio of 20.     

New amperometric immunosensor with response enhanced by PAMAM-dendrimers linked via self assembled monolayers for determination of alpha-fetoprotein in human serum

A new amperometric immunosensor for alpha-fetoprotein (AFP), based on nanobiocomposite substrate and with response enhanced by polyamidoaminic (PAMAM) dendrimers was developed and characterized. The nanostructurated substrate obtained by electrochemical deposition of 100 nm-sized gold nanoparticles on glassy carbon electrodes (GCE) was functionalized by deposition of a SAM of 2-aminoethanethiol (AET), used as linker for the subsequent immobilization of polyamidoaminic dendrimers (PAMAM G.1.5). Two different modes were investigated for the reading of the assay: cyclic voltammetry (CV) or Double Step ChronoAmperometry (DSCA). Satisfying results in terms of response range and precision were reached with both methods. Immunosensors were tested and validated for AFP determination in human serum, showing a limit of detection of 3 ng/mL and a limit of quantitation of 15 ng/mL. The enhanced immunosensor has proved an attractive diagnostic tool able to match the needs of clinical monitoring purposes for AFP quantification in human serum at levels useful both for prognosis of pregnancy progression, and for the identification of the occurrence of neoplastic diseases.