新型分子印迹生物传感器在癌症生物标志物中的应用

癌症生物标志物作为一种特定的身体中可测量的指标，可以通过自身产生的变化来监测癌症健康状况，对于癌症的预防、早期诊断和精准治疗具有重要意义。因此，面向典型疾病标志物的快速检测与精准分析已成为科学研究和临床诊断的热点领域。基于分子印迹的生物传感器由于其灵敏度高、响应速度快、特异性强以及成本低等优点，有望成为癌症生物标志物快速检测的新手段，在癌症临床分析领域得到了广泛研究。本综述简要介绍了分子印迹聚合物的合成方法和策略，分子印迹与电化学、表面等离子共振和光学分析集成的传感技术和手段，以及分子印迹生物传感在癌症生物标志物的应用。最后本综述就目前国内外关于分子印迹传感器在分析检测癌症生物标志物领域的应用现状进行了总结和讨论，并展望了其未来发展前景。     

利用生物传感技术监测分析农药污染的研究

农药的大量生产和广泛使用引发一系列环境污染和食物中毒问题,严重威胁到人类的生存环境和身体健康,生物传感器作为一种便捷、快速检测技术,在农药污染测定中具有广泛应用价值。文章综述了酶生物传感器、免疫传感器、微生物传感器及仿生生物传感器四类生物传感器在农药残留分析中的应用研究,并展望了其发展方向。     

BDD电极修饰及其在生物传感器中的应用进展

生物传感器已被广泛应用于对痕量有机物和生物大分子等物质的检测中,提高生物传感器的检测准确性、检测范围、灵敏度等检测性能是近年来的重点研究内容。掺硼金刚石（BDD）电极基于其优异的物化性质,是目前生物传感器理想的基底材料之一,但其存在价格昂贵、传感性能不高等问题,而化学修饰是提高BDD电极传感性能的有效途径。系统论述了吸附法、共价键结合法和电沉积法3种当前主流的BDD基底修饰方法,在阐述其反应机理的基础上,总结了不同方法所修饰的BDD电极在生物传感器中的应用,并深入分析了各修饰方法的优势和不足。最后,总结了BDD电极作为基底材料应用于生物传感器领域中存在的问题,并展望了未来的重点发展方向,以期为BDD电极的修饰和潜在的实际应用提供新思路。     

纳米材料在电化学生物传感器方面的研究进展与应用

电化学生物传感器是一种利用生物体对特定物质进行选择性识别而开发出的新型化学传感器,它的设计巧妙、构型新颖、用途多样。近年来,为了提高传感器的灵敏度,增加其检测速度,使传感器的稳定性提高并缩小体积,基于纳米材料开发的电化学生物传感器成为分析领域的热点。本文着重介绍纳米材料在电化学生物传感器上的研究与应用。     

基于MOFs材料的化学传感器的研究进展

近几年来,基于金属有机骨架材料(MOFs)材料的化学传感器的研究受到人们的广泛关注,MOFs材料可调的孔尺寸和巨大的比表面积提高了气体检测的选择性和灵敏度。MOFs作为传感材料最大的挑战就是信号的传导,本文详细总结了MOFs化学传感器的信号传导方式,如光学传感(如干涉法、局域表面等离子体共振、胶态晶体、溶剂着色、发光传感等)、导电传感和机电传感(如表面声波传感、石英晶体微天平和微悬臂梁等)等;并展望了MOFs化学传感器的应用前景,合成更多具有导电性质的MOFs材料或将MOFs传感材料与振动光谱及其他分析技术相结合是改善MOFs传感器检测灵敏性和选择性的非常有效的方法。     

基于可控/“活性”自由基聚合的生物传感分析

传统信号放大策略存在成本高昂和操作复杂等不足,无法满足早期诊断等领域的实际应用需求。近年来,科研人员探索建立了一类基于原子转移自由基聚合（ATRP）和可逆加成-断裂链转移（RAFT）聚合等可控/“活性”自由基聚合（CLRP）技术的新型信号放大策略,用于蛋白质和核酸等生物分子的简便、快速、低成本、高灵敏和高选择性检测。本文综述了基于CLRP的生物传感分析的研究进展。首先介绍了生物传感器的概念及特点,简述了传统信号放大策略及基于聚合物的信号放大策略的优缺点。接着,对CLRP技术进行了概述,并重点回顾了基于ATRP和RAFT聚合的信号放大策略在高灵敏生物传感中的应用。最后,对基于CLRP的生物传感分析进行了展望。基于CLRP的信号放大策略,具有操作简便、成本低廉和高效等优良特性,在生物分子的高灵敏检测中具有相当广阔的应用前景。     

光纤光栅用于混凝土结构应变模态检测的研究

光纤Bragg光栅传感技术是一种先进的技术，具有传统技术无可比拟的优势。损伤检测研究是一个跨学科的前沿研究领域，传感技术的发展必将推动混凝土结构损伤检测新技术的研究与应用。本文介绍了光纤Bragg光栅传感技术原理，阐述了基于光纤Bragg光栅传感技术和应变模态理论的损伤自诊断的基本原理，并进行了相关的混凝土结构的可行性实验研究。结果表明光纤Bragg光栅传感器抗干扰能力强，具有高灵敏度和长期稳定性，其作为应变测量的工具用于应变模态，进行混凝土结构损伤识别是可行的。     

基于薄层黑磷的电化学传感器研究进展

自2014年首次被报道以来,层状黑磷作为一种新型的二维纳米材料受到了广泛的关注与研究。层状黑磷具有比表面积大、带隙结构可调、载流子迁移率高、生物相容性好及易修饰等特点,是一类潜在的理想生物传感材料。本文将关注层状黑磷在电化学传感器中的应用,根据检测目标物的类型,对最新的研究报道进行了详细分类与讨论,主要包括气体分子、生物小分子、其他小分子、生物大分子、细胞几大类基于层状黑磷构筑的电化学传感器。重点概述了层状黑磷及其复合纳米材料的制备方法与性质,传感器的结构、工作原理与分析性能等。最后讨论了黑磷基纳米材料在电化学传感器中应用的现存问题和未来发展方向,为进一步拓展黑磷纳米材料在分析传感领域的应用提供了参考。     

MOFs基电化学传感器及其重金属离子检测应用研究进展

现代工业化快速发展，重金属等环境污染严重影响公众健康和生态系统安全。基于MOFs及其复合材料的电化学传感系统是重金属污染物分析检测领域的研究热点。综述了基于MOFs及其复合材料的电化学传感器的构建及其在重金属离子检测中的应用研究进展，简要概述了MOFs材料的组成、结构、分类命名、制备技术、电化学传感优势性能等；探讨了MOFs/碳纳米材料、MOFs/金属纳米材料和MOFs/导电聚合物复合材料应用于电化学传感器的优势特性；详细讨论了MOFs基电化学传感器在Pb²⁺、Hg²⁺和Gd²⁺等重金属离子检测方面的应用研究进展；对MOFs基电化学传感器在重金属离子检测应用中的优势及存在的问题进行了分析，并对未来研究发展趋势进行了展望。     

光电化学传感器研究进展

光电化学(Photoelectrochemical,PEC)生物传感,是一种结合了光电化学分析技术及生物传感技术而发展的新型检测方法。它具备许多独特的优点。因此,光电传感器在分析化学领域占据重要的地位,将具备优越的分析性能用于多种待测物的定量分析。本文对光电化学传感器的发展现状,检测原理,发展趋势进行了论述。     

Photo-Orientation at the Interface between Thermotropic Nematic Liquid Crystal and Water Caused by Azobenzene Polymer Additives

Photoinduced orientational transitions in a thermotropic nematic liquid crystal caused by modulation of the boundary conditions at the water surface were observed and investigated. The initially degenerated planar anchoring of liquid crystal at the water surface becomes homeotropic under near-UV irradiation which induces photoizomerization of comb-shaped azobenzene polymer additives adsorbed from the liquid crystal to its interface with water. After irradiation, the photoinduced orientational structures spontaneously relax to the initial ones. It was shown that the orientational sensitivity to light irradiation strongly depends on the polymerization degree of azobenzene additives.     

Monte Carlo simulations of properties of side‐chain liquid‐crystal polymers

This paper presents a computational conformational study of side‐chain liquid‐crystal polymers to predict the optical and liquid‐crystalline properties of a series of polyepicholorohrdrin, polyacrylate, poly(methyl acrylate), and polystyrene‐based side‐chain polymers using a Monte Carlo simulation method. Some of the simulated side‐chain polymers were synthesised by chemical modification or polymerisation. The predictive capability of the orientational order parameter has been utilised to predict the liquid‐crystalline isotropic transition temperature of the investigated polymers, which was used to infer the type of distribution in the synthesised polymers. The predictive possibilities of this criterion are explored in the estimation of the nematic–isotropic transition temperatures of the simulated polymers. Evidence is presented to suggest that for side‐chain liquid‐crystalline polymer molecules the nematic to isotropic transition occurs when the order parameter reaches a value of 0.43 according to Maier–Saupe mean‐field theory. Copyright © 2006 Society of Chemical Industry     

Effects of droplet size on photorefractive properties of polymer dispersed liquid crystals

Effects of liquid-crystal droplet size on orientational photorefractive properties of the polymer dispersed liquid crystals are investigated experimentally. The composites consist of the same chemical components, but the liquid crystal droplet size was varied by controlling the fabrication process. Particular attention is given to the observation and qualitative and/or quantitative modeling of the resolution, dependence of the applied dc field, dynamics of grating generation and photocurrents, which is strongly dependent on the liquid crystal droplet size.     

Liquid crystal polymer-carbon fiber composites. Molecular orientation

The objective of this work has been to study composite systems in which carbon fibers are dispersed in a liquid crystal polymer matrix. The fundamental point of interest here has been the interfacial response that fiber surfaces can potentially induce in self-ordering polymers. The matrix material used was a thermotropic liquid crystal polyester synthesized in our laboratory from the monomers p-acetoxybenzoic acid, diacetoxyhydroquinone, and pimelic acid. The aromatic-aliphatic polymer was characterized by NMR as a chemically disordered polymer of the three structural units which exhibits a nematic phase at temperatures above 150°C. Breadline proton NMR above the solid to liquid crystal transition was used to measure the rate of magnetic alignment of molecules in the matrix and polarized optical microscopy was used to analyze interfacial zones in composite samples. Fiber surfaces were found to influence the orientation and orientational dynamics of a liquid crystal polymer matrix. This was revealed by enhanced rates of magnetic orientation in the polymer melt when carbon fibers are dispersed in the medium. Fiber surfaces were also found to stabilize nematic ordering of the polymer as the melt was heated towards complete isotropization. The phenomena discovered here may originate in the development of zones around fibers with a common molecular orientation anchored by the carbon surface.     

Electric and Magnetic Field-Assisted Orientational Transitions in the Ensembles of Domains in a Nematic Liquid Crystal on the Polymer Surface

Using electro- and magneto-optical techniques, we investigated orientational transitions in the ensembles of domains in a nematic liquid crystal on the polycarbonate film surface under the conditions of competing surface forces that favor radial and uniform planar alignment of nematic molecules. Having analyzed field dependences of the intensity of light passed through a sample, we established the threshold character of the orientational effects, plotted the calculated intensity versus magnetic coherence length, and compared the latter with the equilibrium length that characterizes the balance of forces on the polymer surface.     

Alignment Photoregulation of a Nematic Liquid Crystal by Surface Adsorption of Aminoalkylated Azobenzenes

Adsorption behavior of azobenzenes having an aminoalkyl residue onto a silica surface is described. Immersion of a silica plate in a benzene solution of an aminoalkylated azobenzene resulted in efficient adsorption to form face-to-face aggregates which are converted into monomeric states by partial desorption. Silica plates adsorbing the azobenzene bearing an aminoalkyl residue were employed to achieve the surface-assisted photoregulation of alignment of a nematic liquid crystal between homeotropic and planar modes. Based on these observations, a convenient method to prepare command surfaces for the orientational photoregulation of liquid crystals was presented by filling a liquid crystal containing an aminoalkylated azobenzene into an empty cell composed of clear silica plates.     

温度对两种不同立方相液晶流变性的影响

分别研究了温度对壬基酚聚氧乙烯醚(NP-10)/水体系和十二烷基聚氧乙烯醚(AEO12)/水体系形成的立方相液晶线性黏弹性的影响。5~23.5℃,NP-10/水体系形成的双连续立方相表现出明显的黏弹性特征,但其强度随温度的升高而降低,在15℃时有强度突变点;连续升温证明,由AEO12/水体系形成的不连续立方相在21.8~22.5℃存在玻璃态转化现象。     

Spatially resolved electron diffraction and the determination of orientational order parameters in thermotropic liquid crystalline polymer

A low-dose, high-resolution, electron-diffraction technique has been used to calculate local orientational order parameters from thermotropic liquid crystal polymer (TLCP) fibers. Diffracted intensities are extracted from digital electron diffraction patterns for the orientational order parameter calculation, in a manner similar to that used with X-ray diffraction data. The resolution of local orientation is made possible by electron diffraction as opposed to other methods because of the ability to sample regions as small as 100 nm in diameter. Working within the critical radiative dose for structural damage constrains the ultimate spatial resolution. The signal-to-noise ratio (SNR) of the diffraction data collected at high spatial resolution is low due to the small volume sampled. This work demonstrates the dependence of the orientational order parameter on signal-to-noise effects and the convergence of the incoming electron beam.     

Topomorphic states and phase transitions connected with the crystallization of polymers

The crystallization of flexible-chain molecules of different degrees of coiling is considered. The nature of the phase transition during crystallization is discussed. The revision of established notions on phase transitions in polymers leads to the concept of crystalline topomorphism, i.e., the existence of two crystalline types with different modes of packing of macromolecules in the macroscopic crystal though they belong to the same lattice class: folded-chain crystal (FCC) and extended-chain crystal (ECC). Phase diagrams in coordinates of degree of coiling vs temperature are plotted. The values of molecular orientation and temperatures at which each of both mechanisms of crystallization takes place are evaluated. The mechanisms of ECC growth under equilibrium conditions and under conditions of molecular orientation are discussed. It is shown that the melting of ECC obtained by the process of orientational crystallization is a second order phase transition, being analogous to a crystal-nematic phase transition. At the same time the melting of FCC provides all the features of a first order transition.     

Characterization of the orientational order in liquid crystalline polymers

Polymers which display liquid crystalline phases are characterized by an orientational order already in the isotropic melt. This order which increases with decreasing temperature involves a parallel local alignment of neighbouring molecules as well as an orientation correlation between molecular axes and the vector, connecting molecular centers. Pretransitional effects take place both at the nematic phase transition and at a second phase transition, occurring at low temperatures.