纳米金在电化学生物传感器中的应用研究进展

近年来,纳米技术的发展为生物传感器的研究注入了新的活力。纳米金由于其独特的光、电学性质、良好的生物相容性、较好的稳定性等特点,可用于分子标记、检测信号放大等方面,从而可以大大改善生物传感器的检测速度、灵敏度、及稳定性。介绍了生物传感器的原理、分类及发展历程、着重阐述了纳米金在电化学生物传感器领域的应用,并对其应用前景做了展望。     

生物传感器基于碳纳米管对环境监测的研究进展

本文综述了碳纳米管的合成、纯化、功能化,基于碳纳米管的电化学生物传感器用于农药残留﹑有污染的阴阳离子及挥发性有机物等环境检测的研究进展。最后,对生物传感器在环境检测中应用前景和发展趋势进行了阐述。     

电化学DNA传感器的最新研究进展:电极修饰材料、探针固定方法和杂交信号检测方法

电化学DNA传感器作为一种新型的生物传感器,在基因诊断及药物分析等方面具有重要的应用价值。结合近年来电化学DNA传感器的研究进展,简述了其检测过程,介绍了DNA电化学传感器所使用的电极修饰材料,详细论述了探针固定技术及信号检测方法,并展望了其发展及应用前景。     

TiO2基光电化学传感器电极结构调控的研究进展

TiO_2因具有无毒、廉价、化学稳定性好以及表面易修饰生物基团等优点,受到研究者的广泛关注。然而,TiO_2存在对太阳能可见光利用率低、光生电子空穴易发生复合等缺点。通过与窄带隙半导体、有机分子、碳材料和贵金属等材料复合,可提高TiO_2的光吸收能力、光生电子空穴分离能力,进而拓展TiO_2的实际应用领域。本文对基于TiO_2的光电化学传感器的研究进展进行了概述,其中重点介绍了通过TiO_2纳米材料的改性来提高TiO_2基光电化学传感器的传感性能,最后提出了TiO_2复合纳米材料光电化学传感器的优势和不足,展望了其未来发展趋势。     

基于石墨烯电化学生物传感器的研究进展

石墨烯具有优良的光电性能和机械性能,是制备电化学生物传感器的绝佳材料。但单质石墨烯易发生卷曲、团聚以及层间堆叠,不利于在传感器中的应用。为此研究人员采取许多措施对石墨烯进行改性,从而得到石墨烯衍生物或石墨烯复合材料,并最终将其应用到电化学生物传感器的制备中。本文简要介绍了石墨烯的功能化方法及在电化学生物传感器中的应用优势,重点综述了基于石墨烯材料的电化学生物传感器,包括免疫传感器、酶传感器、生物小分子传感器、适配体传感器和DNA传感器的最新研究成果,比较分析并总结了各类传感器的优势和不足,展望了其未来的发展前景。     

纳米生物传感器的制备及其在直接电化学中的应用研究进展

基于国内外最新研究进展,系统综述了近年来纳米生物传感器的制备及在直接电化学中的应用研究.着重介绍了纳米生物传感器几种较重要的制备方法,并分析了它们的优缺点;概述了不同纳米生物传感器在直接电化学中的应用及其特点;并对纳米生物传感器的制备方法与应用研究的发展进行了展望.     

基于石墨烯电化学传感器的研究进展

石墨烯由于其独特的性质,在生物及化学检测中的应用日益增多,介绍了石墨烯和功能化石墨烯的性质,着重介绍了近几年基于石墨烯材料的电化学传感器的应用,如各种离子传感器、气体传感器和生物传感器的研究进展及在环境监测、医疗诊断、食品安全等方面的应用,并对石墨烯材料在电化学领域的发展方向和应用前景进行了展望。     

基于ZnO纳米线的酪胺酸霉生物传感器研究

用简单的气相传输法制备了尺度均匀的ZnO纳米线,它具有高等电点、优良的生物兼容性、良好的电子传输特性等优点。基于这些优良特性,酪胺酸霉被稳定的固定于这种纳米材料的表面,进而构建了用于苯酚类物质探测的生物传感器。电化学测试表明这种生物传感器具有高灵敏度、快速响应等优点,可用于环境监测、人体健康等领域。     

石墨烯传感器的研究进展

论述了石墨烯电化学和生物传感器的研究进展,包括石墨烯的直接电化学基础、石墨烯对生物小分子(Hydrogen peroxide,NADH,dopamine,etc.)的电催化活性、石墨烯酶传感器、基于石墨烯薄膜和石墨烯纳米带的实用气体传感器(可检测O2、CO和NO2)、石墨烯DNA传感器和石墨烯医药传感器(可用于检测扑热息痛)。     

喷墨打印制备电化学生物传感器的研究进展

喷墨印刷技术是一种非接触式、工艺简单、无版数字化的印刷技术,越来越多的研究者将该技术应用到制备电化学生物传感器中,以应对电化学生物传感器因向数字化、智能化等方向发展而对其制备技术提出的更高要求。因此,在对喷墨打印技术制备电化学生物传感器原理与优劣进行分析的基础上,依据其发展历程对近年来的研究进行了总结与分析,探讨了其在制作过程中存在的主要问题,即对油墨的要求较高。寻找合适的方法解决喷墨打印金属电极的电导率问题,研究导电聚合物的浓度、层数等对成膜质量和传感器响应程度的影响及利用喷墨打印技术制备整个传感器的研究将是今后本领域的研究重点。     

Removal of Temperature and Earth's Field Effects of a Magnetoelastic pH Sensor

Magnetoelastic sensors are widely used for chemical and biological monitoring including measurement of pH, glucose, carbon dioxide, and Escherichia coli by applying a mass- or elasticity-changing coating that shifts the sensor's resonant frequency in response to the target analytes. However, the sensor's resonant frequency also varies with the ambient temperature and earth's magnetic fields, reducing the accuracy and reliability of the measurements. This paper presents a technique to eliminate the effects of temperature and earth's magnetic field on the magnetoelastic sensor by detecting the change in its higher order harmonic magnetic fields, which are generated by the sensor when excited by a low frequency magnetic field. The higher order harmonic response of the magnetoelastic sensor is a function of temperature and DC field but remains unaffected by the mass/elasticity change from the chemical or biological responsive coating, thus allowing the calibration of both interfering quantities. This paper illustrates the application of this technique on a magnetoelastic pH sensor, where the results show the calibrated measurements are independent from the ambient temperature and DC magnetic fields such as the earth's field.     

Quantification of multiple bioagents with wireless, remote-query magnetoelastic microsensors

This paper presents a micromagnetoelastic sensor array for simultaneously monitoring multiple biological agents. Magnetoelastic sensors, made of low-cost amorphous ferromagnetic ribbons, are analogous and complementary to piezoelectric acoustic wave sensors, which track parameters of interest via changes in resonance behavior. Magnetoelastic sensors are excited with magnetic ac fields, and, in turn, they generate magnetic fluxes that can be detected with a sensing coil from a distance. As a result, these sensors are highly attractive, not only due to their small size and low cost, but also because of their passive and wireless nature. Magnetoelastic sensors have been applied for monitoring pressure, temperature, liquid density, and viscosity, fluid How velocity and direction, and with chemical/biological responsive coatings that change mass or elasticity, various biological and chemical agents. In this paper, we report the fabrication and application of a six-sensor array for simultaneous measurement of Escherichia coli O157:H7, staphylococcal enterotoxin B, and ricin. In addition, the sensor array also monitors temperature and pH so the measurements are independent from these two parameters.     

特殊结构露点传感器的校准特点

露点仪、露点传感器作为环境湿度的检测仪器,广泛使用于工农业生产、工业自动化和生活的各个领域。本文通过对露点传感器校准的现状分析,指出了目前的校准方法中存在的尚不具体明确之处。本文分析了特殊露点传感器结构原理,由此改进了特殊结构露点传感器的校准方法。     

Ferrite-Piezoelectric Multilayers for Magnetic Field Sensors

A magnetic field sensor based on magnetoelectric effects in a ferrite-piezoelectric layered sample is proposed. Such sensors are passive, provide direct conversion of magnetic fields into an electrical signal, and allow measurements of both ac and dc magnetic fields. A multilayer sample of nickel zinc ferrite-lead zirconate titanate has been used to characterize the sensor response to ac and dc fields, field orientations, frequency, and temperature. The sample shows a linear response for dc fields up to a maximum of 1750 Oe. The sensor output is temperature independent over 273–337 K, but is dependent on frequency of the ac excitation field. Operating at electromechanical resonance for the element enhances the sensor sensitivity by an order of magnitude. For ac magnetic field sensors, the output varies linearly with amplitude.     

The potential of microacoustic SAW- and BAW-based sensors for automotive applications - a review

In recent years, sensors and sensor systems have gained increasing importance for automotive electronics. In this paper, the suitability and the perspectives in the application of microacoustic surface- and bulk-acoustic-wave sensors in the fields of angular rate sensors, pressure sensors, wireless sensor readout, and liquid sensors are discussed.     

Research Progress of Organic Field-Effect Transistor Based Chemical Sensors

Due to their high sensitivity and selectivity, chemical sensors have gained significant attention in various fields, including drug security, environmental testing, food safety, and biological medicine. Among them, organic field-effect transistor (OFET) based chemical sensors have emerged as a promising alternative to traditional sensors, exhibiting several advantages such as multi-parameter detection, room temperature operation, miniaturization, flexibility, and portability. This review paper presents recent research progress on OFET-based chemical sensors, highlighting the enhancement of sensor performance, including sensitivity, selectivity, stability, etc. The main improvement programs are improving the internal and external structures of the device, as well as the organic semiconductor layer and dielectric structure. Finally, an outlook on the prospects and challenges of OFET-based chemical sensors is presented.     

Langmuir-Blodgett films as chemical sensors

This review covers the fundamental scheme of chemical sensors, fields of major interest in chemical sensors with Langmuir-Blodgett (LB) films, and new and future trends in LB sensor studies. The topics discussed are the relation between sensor characteristics and LB film structure, the biomimetic approach to sensor developments, proposals for transducer improvements, and the possibility of fabricating molecular filters by LB techniques.     

A Resonant Micromachined Magnetic Field Sensor

The design, modeling, and simulation of a novel micromachined magnetic field sensor are discussed. The sensor uses an electrostatic resonator whose fundamental resonant frequency is modified by a Lorentz force generated from the interaction of the sensor structure and the present magnetic field. The sensor was fabricated in a standard bulk micromachining process without the need for any additional processing steps. Since the sensor does not employ any magnetic materials, it does not exhibit hysteresis. A comprehensive model of the sensor behavior is derived which encompasses the interactions of the involved physical domains. Validity of the modeling results was verified by finite-element simulations, and later, through experiments. The sensitivities of the fabricated sensors are in the range of 48-87 Hz/T, depending on sensor structure and dimensions. The design of the sensor allows for its fabrication in many standard microelectromechanical system processes and is compatible with CMOS processes. The theoretical minimum detectable signal with current devices is on the order of 217 nT. Methods to improve the sensitivity of the current sensors are suggested. A linear response to a wide range of magnetic fields makes this design suitable for applications where large fields need to be measured with high resolution.     

A novel gas sensor based on field ionization from ZnO nanowires: moderate working voltage and high stability

We report a kind of gas sensor using ZnO nanowires as the field ionization anode. The sharp tips of nanowires generate very high electric fields at relatively low voltages. The sensors show good sensitivity and selectivity. Moreover, the detection limitation of the field ionization based ZnO nanowire gas sensors is about 5%. More importantly, a sensor with ZnO nanowires as the anode exhibits an impressive performance with respect to stability and anti-oxidation behavior, which are significantly better than those of carbon nanotubes (CNTs) as electrodes. Therefore, the simple, low-cost, sensors described here could be deployed for a variety of applications.     

A high-sensitivity, dual-plate, thickness-shear mode pressure sensor

We propose a dual-plate pressure sensor operating with pressure-induced frequency shifts of thickness-shear modes of a crystal plate resonator. Under an applied normal pressure. The dual-plate structure causes flexure in the crystal plate rather than circumferential compression in usual thickness-shear pressure sensors. This suggests higher sensitivity because a plate responds to a normal pressure more than to a circumferential compression, which is shown by a theoretical analysis using the theory for small fields superposed on initial fields.