压电传感器在环境监测中的应用

简要介绍了压电石英晶体微天平（ＱＣＭ）及表现声波（ＳＡＷ）压电传感器的基本原理，从ＱＣＭ化学传感器毒气检测、ＱＣＭ化学传感器液相检测、ＳＡＷ化学传感器分析、压电生物传感器物质分析、压电生物传感器液相分析、压电传感器陈列、非质量效应压电传感器等方面介绍了近年来压电传感器在环境监测领域的研究进展，并展望了压电传感顺在环境监测中的应用前景。     

压电生物传感器

虽然压电效应在上一世纪业已发现,但是压电石英晶体在化学传感器中的应用却是1995年Sauerbrey导出了频率-质量关系式之后才实现的.1964年King报道了第一个压电石英晶体检测器.至今,压电石英传感器已广泛用于气体、液体试样分析.我国姚守拙等人在压电石英晶体的分析应用领域率先进行了大量的研究工作.根据Sauerbrey方程,结合生物体中某些高选择反应,通过对石英晶体表面进行修饰,使其能选择性地与被检测物质作用,便可制成压电生物敏感元件(或压电生物传感器).1972年Shons首次用抗原涂膜压电晶体来检测溶液中的抗体,由于当时技术的限制及人们对该类传感器认识不足,未能得到较好地发展,直到本世纪80年代中期才为人们所重视.目前国外对此新领域的研究非常活跃,但国内尚未见压电生物传感器方面的研究报道.现对     

压电石英晶体生物传感器技术要点及展望

简介了生物传感器的分类,重点介绍了压电石英晶体生物传感器的基本原理、基本构成、检测流程、振荡电路、检测池的设计、固定化技术等内容,分析了压电石英晶体生物传感器的特点及研究中存在的不足,并对今后的研究方向提出一些看法与展望.     

压电生物传感器研究进展①

压电生物传感器是一种新型的生物传感器，它将压电传感器的灵敏性和生物反应的特异性结合在一起。与传统的生化分析方法相比，压电生物传感器具有结构简单、不需要标记、检测时间短等特点。近年来，压电生物传感器在临床诊断、生物技术、食品卫生检验等领域得到了广泛的应用。本文对压电生物传感器的研究现状作了综述，讨论乐压电生物传感器在各个领域的应用，压电生物传感技术的关键问题，以及不同种类的压电生物传感器。     

压电石英晶体生物传感器应用研究进展

压电石英晶体生物传感器是利用压电石英晶体振荡频率对晶体表面质量负载和表面性状如密度、粘度、电导、介电常数等的高度敏感性与生物识别分子的高度特异性相结合发展起来的一种新型传感器。它具有灵敏度高、特异性好 ;操作简单 ,不需任何标记 ;检测速度快 ,成本低廉 ;能实时检测等特点。近年来 ,压电石英晶体生物传感器在医学实验诊断、军事监控、环境监测、食品卫生检验、工业生产实时监测等野外流动作业和在线检测等领域得到广泛应用。     

压电石英晶体传感器在单链及乙肝病毒检测中的应用

建立压电石英晶体传感器检测乙肝血液样品的方法。在石英晶体表面固定单链DNA,构建压电晶体DNA生物传感器,然后,分别与乙肝病毒的特异性片段和处理过的乙肝血液样品进行杂交反应。DNA传感器能较好地诊断出血清中的HBV病毒基因。压电石英晶体传感器操作方便、省时,且具有较好的准确度,在临床诊断中有很好的前景。     

DNA生物传感器的进展

DNA生物传感器是分子生物学与微电子学、电化学、光学等相结合的产物 ,它将在生命科学与信息科学之间架起一道桥梁 ,成为DNA信息分析检测最重要的技术之一。简要介绍了电化学DNA生物传感器、压电石英晶体DNA生物传感器、光学DNA生物传感器的结构原理     

基于压电基因传感器的DNA计算

压电基因传感器是一种新型的生物传感器,它把压电传感器的灵敏性和DNA杂交反应相结合．与传统的基因检测技术相比,它具有结构简单、无需标记、检测时间短、检测信号易处理等特点．将它用于分子运算,与常规的DNA芯片相比,它的检测结果更易于进行自动化处理,因此便于构建大规模的分子运算机器．文中在压电基因传感器和新兴学科DNA计算的基础上,给出了解决0-1规划问题新的DNA计算方法,并指出以前两种基于表面DNA计算在解决这一问题时的不足．与以往的DNA计算方法相比其输出的是电信号,因此具有操作易自动化、识别解更方便和高信息量的优点．与使用常规DNA芯片的表面DNA计算相比,使用压电基因传感器进行DNA计算可以克服可行解识别困难的问题．压电基因传感器技术有望成为新的分子运算工具,可作为构建自动化的DNA计算机的基础．     

用于液相检测的双参数压电DNA传感器研究

采用自组装技术,利用亲和素-生物素系统将25-mer的生物素标记的DNA探针固定于石英谐振器金电极上,与双参数压电传感器相结合,研制成了用于液相检测的压电DNA传感器。该传感器稳定性较好,3h频移在5Hz以内;液体的体积在一定范围内对双参数传感器未见明显影响;用双参数方法制作的传感器特异性等性能较好,为实现检测的自动化和生物的动力学测定打下了基础。     

基于加速度传感器的高频振动信号检测分析

介绍了一种基于普通压电加速度传感器的高频振动信号检测技术的实现方法,并论述了高频振动信号的采集、时域分析、频域分析及功率谱分析程序的实现。检测系统硬件部分主要包括压电加速度传感器、信号调理器、高速采集卡。用这套检测系统对各频段的信号进行检测对比实验,实验结果表明此系统能有效地检测到高频振动信号的变化。     

压电生物传感器及其信号放大技术

压电生物传感器是结合了压电效应的高灵敏性和生化反应的高特异性的一种生物传感器,在生物技术、临床诊断、环境监测、食品卫生等领域具有广泛的应用前景.该文介绍了压电生物传感器的基本原理、分类及应用领域,同时重点对基于电极表面修饰技术、纳米材料、酶催化等压电生物传感器的信号放大技术做了较为系统全面的综述.     

Enzyme-immobilized SH-SAW biosensor

A shear horizontal mode surface acoustic wave (SH-SAW) device has many attractions for chemical-sensing applications in liquid media. The SH-SAW that propagates on 36° rotated Y-cute, X-propagating LiTaO₃ is affected by a strong acoustoelectric interaction between the piezoelectric potential and electric properties of the adjacent liquid. This paper describes an enzyme-immobilized SH-SAW biosensor in which the detection principle is the acoustoelectric interaction due to the pH change in the enzyme reaction. Two kinds of enzymes, urease and cholinesterase, are immobilized on the sensor surface and highly sensitive detection of the enzyme reaction is obtained experimentally. The urease-immobilized SH-SAW biosensor is implemented in a liquid-flow system. By using the cholinesterase-immobilized SH-SAW sensor, we have succeeded in detecting an inhibition effect of a pesticide.     

Development of miniaturized piezoelectric actuators for opticalapplications realized using LIGA technology

To combine the advantages of the LIGA technology and piezoelectric materials, first prototypes of movable elastic LIGA structures have been realized on piezoelectric substrates. The structures consist of a flexible beam fixed to the piezoelectric substrate at its two ends in order to amplify the d₃₁-contraction of the piezoelectric substrate. By using this flexible LIGA beam as a magnification mechanism, the small displacements of the piezoelectric substrate are amplified by more than a factor of 20, offering various possibilities of applications, especially in micro-optics. In this paper, first the fabrication process and the performance of these new prototypes of LIGA piezoelectric actuators are described in detail, demonstrating the feasibility of the new concept combining the LIGA technique and piezoelectric substrates. Subsequently, LIGA-piezoelectric actuators developed for micro-optical applications are presented. These new optical actuators are also based on an elastic beam but slightly modified in order to modulate light propagating in optical fibers. They find promising applications as micro-optical attenuators or choppers whose performance is demonstrated     

电容式生物传感器应用研究进展

电容式生物传感器是近年来出现的新型传感器,其突出优点是灵敏度高、结构简单、易于集成,无需标记物可以直接检测特异性抗体、抗原、蛋白质、DNA片断及重金属离子等。介绍了电容式生物传感器的应用研究现状,指出了目前存在的问题及将来的发展方向。     

Numerical simulation for sensitivity and accuracy enhancement of micro cantilever-based biosensor employing truss structure

Micro-cantilevers are very effective and reliable devices for bio-sensing applications. In this work, a novel biosensor based on micro-cantilever array was designed, simulated and optimized for different bio-sensing applications with high sensitivity, high accuracy, high throughput, and high Q factor. A truss structure designed in the anchored end of the micro-cantilever which was effective in improving the sensitivity to increase detection accuracy. Also, the effects of the surrounding medium are minimized by this structure to achieve high Q factor and longer vibration for bio-sensor. All the results are compared by the conventional micro-cantilever. As a result, the Q factor is increased from 52.1 to 126.1 within water medium and from 51.8 to 120 within ethanol medium. The actuation of novel MCL is simulated by different piezoelectric materials, the results proof that the amplitude of displacement for the PZT-5H is more efficient than AlN.

     

Thin-film electro-acoustic sensors based on AlN and its alloys: possibilities and limitations

Sputter deposited aluminum nitride (AlN) thin films have played a central role for the successful development of the thin film electro-acoustic technology. The development has been primarily driven by one device—the thin film bulk acoustic resonator, with its primary use for high frequency filter applications for the telecom industry. Recently, increased piezoelectric properties in AlN through the alloying with scandium nitride have been identified both experimentally and theoretically. This opens up new possibilities for the thin film electro-acoustic technology. Here expectations and discussions are presented on acoustic FBAR sensor performance when based on AlN as well as on such AlN alloys to identify possible benefits and limitations. Inhere, the distinction is made between direct and in-direct (acoustic) use of the piezoelectric effect for sensor applications. These two approaches are described and compared in view of their advantages and possibilities. Especially, the indirect (or acoustic) use is identified as interesting for its versatility and good exploitation of the thin film technology to obtain highly sensitive sensor transducers. It is pointed out that the indirect approach can well be obtained internally in the piezoelectric material structure. Original calculations are presented to support the discussion.