基于纳米孔器件的光响应分子的应用

探索生物大分子和小分子的构象以及它们在外界环境中的响应和作用规律对理解有机质的结构与性能的关系十分重要。纳米孔作为新兴的第三代单分子基因测序技术,可以实时监测待测物分子的构象变化过程,在单分子检测及核酸和蛋白测序方面展现了良好的应用前景。为了进一步提高检测的分辨率和精确度,可以采用光电联合检测方法,通过引入光响应分子以满足更高的检测需求。本文综述了目前纳米孔器件的研究进展以及代表性光响应分子在纳米孔检测系统中的设计与应用,主要介绍了偶氮苯及其衍生物、螺吡喃和二芳基乙烯三类光响应分子分别在生物孔和固态孔中的光响应性能。光调控是一种操作简捷有效的分子结构监控方式,其与纳米孔检测技术的结合在单分子识别方面的应用潜力对多功能纳米器件的设计与应用具有重要的指导意义。     

基于高分子聚合物及毛细玻璃管的固态单纳米孔通道在分析化学中的应用

纳米孔检测技术以其独特的优势在电分析化学领域引起广泛的关注,基于此构建的电化学传感器及电化学整流开关已被用于多种目标物分析,如单分子蛋白检测及DNA测序。纳米孔既可由生物分子制成,也可由固态材料制备。其中,固态纳米孔易于修饰,机械性能、稳定性等相对较好,应用较为广泛。纳米孔检测技术主要的输出信号为电阻脉冲和电流-电压曲线(离子整流),本文以两种输出信号为重点,详细介绍了纳米孔检测的原理和应用,总结了近年来固态单纳米孔通道在分析化学领域的发展,并对该领域未来的发展趋势和应用前景进行了展望。     

生物纳米孔分析技术研究进展

生物纳米孔传感技术因其快速、低成本、无需荧光标记等优点,在化学和生物等诸多研究领域得到广泛应用,已发展成为一种新颖的、独具特色的单分子分析手段。该技术目前主要应用于DNA测序研究,同时在单分子分析领域也取得了令人瞩目的成就。该文简要介绍了生物纳米孔分析技术的原理和生物孔的种类,主要总结了近20年来生物纳米孔在DNA测序和单分子分析中的研究进展并予以了展望。     

固态纳米孔对蛋白质易位的实验研究

蛋白质因其多样性和功能性,是生物体内一类非常重要的分子.通常蛋白质的表征需要借助荧光或者酶的标记.而纳米孔技术,得益于免标记、单分子检测等优势,为蛋白质的表征提供了新方向.我们使用固态纳米孔完成了单个蛋白质分子及蛋白质-蛋白质结合物的检测.可以发现,外部电压和电解质溶液的酸碱度会直接影响蛋白质分子表面带电量,从而加快或延迟其在孔内的易位时间.抗原、抗体本质上都是蛋白质,两者之间具有高度特异性.通过比较抗体溶液在添加特异性抗原前后的易位事件,实现了单个蛋白质分子和蛋白质-蛋白质结合物的区分.未来,纳米孔技术有望应用于多蛋白质分子的辨识、蛋白质分子相互作用机制等方面的研究.     

生物大分子纳米孔分析技术研究进展

脱氧核糖核酸穿越纳米孔动力学研究以及利用纳米孔开展新型DNA测序技术研究是后人类基因组计划的热点之一。本文对生物纳米孔、固态纳米孔以及纳米孔生物大分子识别技术的研究现状进行了归纳和总结,并对该领域的发展趋势进行展望。     

生物纳米孔道技术在非基因测序方面的研究与应用

纳米孔道分析技术是一种低成本、快速、无需标记的单分子检测技术,仅有20多年的发展历史,在DNA单分子测序领域展示出较好的应用前景,现已有商业化的产品面世且趋于成熟.越来越多的研究表明,纳米孔可作为一个通用的单分子传感器.本文综述了生物纳米孔道分析技术对蛋白质、多肽和核酸等单个分子与孔道间相互作用、动力学和热力学过程的实时监测以及多种生物大分子和金属离子的定量检测等方面的研究进展.在纳米孔技术中,电化学检测系统也十分重要,本文还特别介绍了高带宽及超低电流分辨仪器和相关软件的相关进展.     

受限纳尺度下蛋白质输运的主动操纵技术

蛋白质是人体细胞、组织的重要组成部分,与众多代谢活动密切相关,它们的一些微小改变就可能引发人体的重大疾病.因此,蛋白质检测是生物化学领域的重要课题.纳米孔技术能够在单分子水平甚至单氨基酸水平上实时检测蛋白质,有望成为最低成本和最高效的蛋白质检测方法之一.然而,使用纳米孔检测蛋白质时,由于实验条件和检测策略的原因,使得蛋白质在纳米孔中驻留时间过短,无法从蛋白质捕获的电信号中清晰地反映更多的生物细节信息.解决这一问题的关键在于控制蛋白质通过纳米孔时的输运速度,满足传感器件带宽的要求.本综述从外部力场竞争、内部力场相互作用、亲疏水相互作用、空间位阻效应等角度综述了蛋白质在纳米孔中输运的主动操纵技术,目的是提高纳米孔对蛋白质的捕获频率,延长蛋白质在纳米孔内的驻留时间,以实现高分辨率的蛋白质检测,充分揭示蛋白质分子的构象变化机制、反应动力学,甚至实现蛋白质测序等.最后对纳米孔传感技术在蛋白质检测方面存在的巨大挑战和发展趋势进行了详细展望和总结阐述.     

纳米孔分析方法在有毒物质检测中的应用

纳米孔技术作为一种新型的分析检测方法,被广泛应用于核酸测序、蛋白质/多肽分析以及病毒、微生物等生物大分子和金属离子的检测。随着人们对公共安全和食品药品安全等问题的日益关注,对有毒物质的检测也提出了更高的要求。鉴于纳米孔分析方法具有高灵敏度和高选择性等优点,很多研究团队将其应用于有毒物质的检测,进行了很多的研究工作。本文针对近年来纳米孔技术在有毒物质检测中的应用进行综述,并对其应用前景进行了展望。     

固体纳米孔分析技术的研究进展

纳米孔分析技术是一种低成本、无需荧光标记和扩增的单分子检测技术,其中基于固体材料的纳米孔由于稳定性高、耐受性好、尺寸可控、易于修饰等优点,在化学和生命科学等领域得到广泛应用。固体纳米孔主要由薄膜和管材料两种类型材料制备,其中常见的薄膜纳米孔包括氮化硅、二维材料、氧化铝以及聚合物薄膜,管材料主要包括玻璃毛细管和碳纳米管。本文总结了固体纳米孔分析技术的研究进展,展望了发展前景。     

固相纳米孔对核酸组装的“免标记、均相”表征和应用探索

随着核酸自组装领域的飞速发展,除了作为遗传信息的载体外,核酸成为了一种具有高操作自由度和无限可能性的功能材料.基于核酸自组装原理的DNA纳米技术凭借其强大的可编辑性已经广泛应用于生物传感、纳米材料工程、医学诊疗以及分子计算机等领域.纳米孔作为一种新兴的单分子分析技术具有高分辨、高通量、免标记等特点,近年来在基因测序、分子物理化学性质分析等领域展示出了极大的应用潜力.作为一种新型高分辨表征技术,纳米孔已经在DNA纳米技术研究中崭露头角,被用于原位追踪和分析核酸分子的自组装行为.另一方面,DNA纳米技术也为纳米孔传感所面临的技术瓶颈提供了更多样化的解决思路,如借助功能核酸(Aptamer或DNAzyme)和无酶扩增核酸分子线路实现纳米孔对待测物的特异性增敏检测.本专论旨在通过对近期纳米孔技术与核酸自组装的跨领域研究成果进行系统性回顾,总结并展望纳米孔传感领域内核酸自组装的研究进展,以期为单分子生物分析、信息检索、基因分型和临床诊断等领域提供新思路和新方法.     

Indirect Electrosorptive Detection via Kinetic Facilitation in Ion Chromatography

Abstract

A new technique based on electrosorption is presented for the determination of selected anions in ion chromatography. Unlike conventional methods, which are based on the measurement of nonfaradaic currents, the present method utilizes a kinetic facilitation imparted to the electroreduction of a cationic “adsorbate probe” by specifically adsorbed anions, and hence involves the measurement of faradaic currents. Amminated, transition-metal salts of Co(III) have been found most useful as adsorbate probes for this application. The current enhancement-analyte concentration response curves obtained were determined to be linear over a limited range at mercury, but show curvature at virtually all concentrations at silver. Detection limits for this technique are slightly higher than those realized using more conventional double-layer capacitance methods. A brief discussion of the future prospects for this new approach is given.     

单碱基多样性的非测序检测

单碱基多样性（SNP）是最常见的基因突变形式之一,经研究证明与很多疾病相关。虽然测序是检测SNP的重要方法,但其需要检测仪器,且检测时间较长,限制了其临床应用。本文综述了SNP的常见非测序分析方法。首先讨论了检测的热力学问题,并归纳了主要的检测策略：基于杂交的检测,基于链取代反应的检测和酶介导的检测。在三维均相检测方法中,主要介绍了不同信号开关策略,如荧光开关、酶识别开关和场效应开关。三维原位检测不仅能检测SNP,还能提供其细胞定位信息,在细胞异质性较高时更具优势。二维界面检测的识别反应速率和杂交效率受到一定影响,但界面检测能进一步减小干扰,亦便于实现高通量检测。以DNA正四面体探针界面为代表的改良界面具有优良的灵敏度和特异性。同时本文亦讨论了现有方法的局限性,并对SNP非测序检测研究进行展望。     

A 2D cadmium metal–organic framework: Synthesis,structure and luminescence sensing for chromate,permanganate, cupric,silver and ferric

A multi-responsive Cd metal–organic framework {[Cd (ttpe)(H₂O)(ip)]•4H₂O•DMAC}_n ( 1•4H ₂ O•DMAC ) was synthesized using hydrothermal method (ttpe = 1,1,2,2-tetra(4-(1H-1,2,4-triazol-1-yl)phenyl)ethylene, ip = isophthalate, DMAC = N,N-dimethylacetamide), and characterized. 1 exhibits a 2D (4,4) network. The luminescent sensing experimrnts showed that 1•4H ₂ O•DMAC as a new MOF luminescent sensor can detect Cr₂O₇²⁻, CrO₄²⁻, MnO₄⁻, Cu²⁺, Ag⁺ and Fe³⁺ in aqueous solution with simultaneously high efficiency and high sensitivity. The quenching constants K_sv for Cr₂O₇²⁻, CrO₄²⁻, MnO₄⁻, Cu²⁺, Ag⁺ and Fe³⁺ are 4.231 × 10⁴ M⁻¹, 2.471 × 10⁴ M⁻¹, 6.459 × 10³ M⁻¹, 7.617 × 10³ M⁻¹, 1.563 × 10⁴ M⁻¹ and 3.574 × 10⁴ M⁻¹, respectively. The detection limits are 0.094 μM for Cr₂O₇²⁻, 0.108 μM for CrO₄^{2 −} , 0.346 μM for MnO₄⁻, 0.302 μM for Cu²⁺, 0.221 μM for Ag ⁺ , and 0.100 μM for Fe³⁺. 1•4H ₂ O•DMAC exhibits high photocatalytic efficiency for degradation of methylene blue under visible light irradiation.     

Surface-enhanced Raman scattering for protein detection

Proteins are essential components of organisms and they participate in every process within cells. The key characteristic of proteins that allows their diverse functions is their ability to bind other molecules specifically and tightly. With the development of proteomics, exploring high-efficiency detection methods for large-scale proteins is increasingly important. In recent years, rapid development of surface-enhanced Raman scattering (SERS)-based biosensors leads to the SERS realm of applications from chemical analysis to nanostructure characterization and biomedical applications. For proteins, early studies focused on investigating SERS spectra of individual proteins, and the successful design of nanoparticle probes has promoted great progress of SERS-based immunoassays. In this review we outline the development of SERS-based methods for proteins with particular focus on our proposed protein-mediated SERS-active substrates and their applications in label-free and Raman dye-labeled protein detection. Figure Protein-mediated SERS-active substrates for protein detection     

Integration of Separation Capillary with a Au Film Electrode and an Etched Decoupler in Amperometric Capillary Electrophoresis

Introduced in this article is fabrication of an integrated capillary for the applications of electrochemical detection in capillary electrophoresis. The separation section, voltage decoupler, and working electrode were composed into a single section of capillary. The porous decoupler was constructed by HF etching till the thickness of the capillary wall less than 20 μm. The working electrode was prepared by sputtering Au-films on the outlet of the capillary. The integration of the separation capillary with a complete detection assembly improves the convenience for the routine application of electrochemical measurements in capillary electrophoresis. For a 100-μm-i.d. capillary, the theoretical plate number of catechol and the migration time reproducibility can reach 120,000 and 1.9% RSD, respectively. The linear range exceeds 3 order of magnitude and the detection limit is lower than 0.65 μM.     

Amperometric multidetection with composite enzyme electrodes

The use of composite biosensors for multianalyte detection strategies is discussed. Graphite–Teflon rigid composite biosensors offer the possibility of coimmobilization of several enzymes by simple physical inclusion in the bulk of the electrode matrix with no covalent linkages. A novel trienzyme graphite–Teflon–glucose oxidase (GOD)–alcohol oxidase (AOD)–peroxidase (HRP)–ferrocene bisosensor yielded amperometric steady-state currents similar to those obtained with graphite–Teflon–GOD–HRP–ferrocene and graphite–Teflon–AOD–HRP–ferrocene electrodes for the same concentration of glucose and ethanol, respectively. The performance of the trienzyme biosensor for multianalyte detection was evaluated with the simultaneous determination of glucose and ethanol after separation by HPLC, in samples of sweet wine. The simultaneous analysis of several analytes in the same sample should imply that, with an adequate dilution, the concentration levels of the analytes can be included within the ranges of linearity of the corresponding calibration plots. The use of two composite biosensors in a parallel configuration, so that different analytes can be simultaneously detected with no need of chromatographic separation, is also discussed. The usefulness of this approach was evaluated by the simultaneous analysis of glucose and ethanol in sweet wine, and of glucose and lactic acid in red wine.     

光照度探测器设计与精度校正

助航灯光系统为夜间或能见度较低环境下飞机的安全起降提供安全保障。快速准确地测量和判断其光强等级、光照射角等是否符合国际民用航空组织(ICAO)的标准,是保障机场安全运行的重要工作。本文设计了基于硅光电池的照度探测器,通过余弦校正器和不同滤光片的组合完成视见函数校正和照度探测的精度标定,实现了灯光的高速动态检测;完成了光照度探测器的线性标定和动态精度测量实验,照度测量误差率和动态测量误差均满足ICAO规定的要求;实现了助航灯光平行截面内光强的高速动态检测。     

Chromenone-rhodamine conjugate for naked eye detection of Al3+ and Hg2+ ions in semi aqueous medium

Chromenone-rhodamine conjugate 1 has been synthesized and its metal ion binding properties have been studied in CH₃CN/water (3:1, v/v; 10 mM HEPES buffer; pH = 6.85). Compound 1 senses multiple metal ions such as Al³⁺ and Hg²⁺ by exhibiting turn on fluorescence and color change (colorless to pink). Al³⁺ and Hg²⁺ ions have been distinguished with the aid of tetrabutylammonium iodide (TBAI). While in the presence of I^? the pink color of the 1.Hg²⁺ complex was completely discharged; under identical conditions the pink color of 1.Al³⁺ complex was retained.     

A review of reaction detection in HPLC

Summary In the past decade, reaction detection has rapidly gained importance as a means to improve the sensitivity and selectivity of detection in HPLC. Today, most attention is being paid to post-column reaction detection with final analysis via fluorescence monitoring. Novel developments involve the use of solid-phase reactors for reagent addition or catalysis (ion-exchange resins, immobilized enzymes), and the increasing use of systems based on peroxyoxalate chemiluminescence detection. The rapidly growing number of reported applications indicates that commercialization of reaction-detection equipment is urgently needed.