Fluorescence Sensors Based on Aggregation Induced Excimer Emission

荧光信号对环境变化的敏感程度主要取决于其产生本源。一般而言,聚集诱导激基缔合物荧光对其所处微环境变化异常敏感,因而引起了荧光传感器研究领域学者的高度关注。除此之外,荧光传感器的传感性能还与其所采用的荧光物种的类型和传感元素的结构密切相关。基于这些认识,本文概括介绍了笔者实验室多年来以聚集诱导激基缔合物荧光为基础的荧光传感器研究进展,特别是以芘为例,系统介绍了该类传感器在液相或气相中的检测应用,其中部分传感器已经实现了仪器化。同时,还介绍了由本课题组提出的用于理解荧光薄膜传感器传感机理和指导新型传感薄膜设计的"二维溶液模型"。最后,展望了荧光传感器研究和应用前景,指出了此类研究面临的主要挑战。     

薄膜基荧光气体传感器

薄膜基荧光传感因灵敏度高、可采集信号丰富、实时检测性好和易于器件化等优点备受人们关注,特别是随着微纳米加工、集成制造和物联网技术的发展应用,薄膜基荧光传感器研究已经成为传感器研究的一个重要领域,呈现出广阔的发展前景。 结合课题组工作,本文简要讨论了基于小分子化合物的薄膜基荧光气体传感器在隐藏爆炸物、毒品、挥发性有机污染物检测/监测,重大疾病早期诊断等领域的应用探索。 在此基础上,指出了薄膜基荧光传感器发展面临的问题,评述了薄膜基荧光传感器研究和应用的前景。     

LDHs薄膜基纳米荧光传感器的制备及其研究进展

层状复合氢氧化物(LDHs)是一种层板金属元素和层间离子可调的无机层状材料,利用其独特的插层组装特性,基于静电、氢键、范德华力等相互作用力,功能性荧光客体分子可与LDHs纳米片复合构筑多功能荧光薄膜材料.LDHs薄膜基荧光材料用于荧光传感器,在有机挥发性气体(VOCs)、温度、压力、重要生物分子等的检测中显示了良好性能.本文总结了LDHs复合薄膜的制备方法以及近年来其在纳米荧光传感领域的进展,并对其未来发展做出了展望.     

聚集诱导激基缔合物荧光传感器(英文)

荧光信号对环境变化的敏感程度主要取决于其产生本源。一般而言,聚集诱导激基缔合物荧光对其所处微环境变化异常敏感,因而引起了荧光传感器研究领域学者的高度关注。除此之外,荧光传感器的传感性能还与其所采用的荧光物种的类型和传感元素的结构密切相关。基于这些认识,本文概括介绍了笔者实验室多年来以聚集诱导激基缔合物荧光为基础的荧光传感器研究进展,特别是以芘为例,系统介绍了该类传感器在液相或气相中的检测应用,其中部分传感器已经实现了仪器化。同时,还介绍了由本课题组提出的用于理解荧光薄膜传感器传感机理和指导新型传感薄膜设计的"二维溶液模型"。最后,展望了荧光传感器研究和应用前景,指出了此类研究面临的主要挑战。     

薄膜荧光传感

<正>不同于其它探测技术,荧光以激发态实现传感。因此,荧光传感具有灵敏度高、可设计性好、仪器结构相对简单、能耗低、不涉及放射性源、易于实现便携等优点,受到了人们的特别关注^1,2。薄膜荧光传感是荧光传感的一种重要形式,是继离子迁移谱技术之后最具发展潜力的可实现便携的气相微痕量物质探测技术。敏感薄膜创制是薄膜荧光技术的核心,薄膜性能主要取决于决定传感发生机制的传感单元,以及影响传感对象分子吸附、解析和扩散的活性层(adlayer)结构。一般而言,     

薄膜基荧光传感检测的研究进展

薄膜基荧光传感器是继离子迁移谱之后,业界公认的一种最具发展潜力的微痕量物质探测技术.由于其具有灵敏性、便携性、实时检测、响应速度快、易于制造、不污染待测体系等优点,在食品检测、环境监测、质量控制和生物医学分析等领域引起了广泛的关注和研究.本文主要综述了近年来薄膜基荧光传感在挥发性气体检测、有毒化学品检测、爆炸物检测、溶液相离子检测以及生物监测等领域的研究进展,并提出了薄膜基荧光传感所面临的挑战与未来的发展方向.     

薄膜荧光传感器研究进展

按薄膜荧光传感器的制备方法, 从物理薄膜、化学薄膜和自组装单层膜等三个方面综述了近年来薄膜荧光传感器的研究进展. 在此基础上, 展望了薄膜荧光传感器的研究前景.     

基质表面多环芳烃的化学单层组装及其荧光传感特性

经由柔性连接臂化学单层组装于基质表面的多环芳烃,在基质表面有限区域内可以形成特定的超分子结构,并呈现相应的荧光光谱.这类结构及其光谱性质可因环境条件的变化而变化,基于这种变化可以设计制备传感薄膜材料.本文在概述此类研究工作的基础上,重点介绍了笔者实验室近年来,通过改变基质类型、调节连接臂长度和结构、优化多环芳烃的固定化密度等途径,设计制备对有关化学物质敏感且既可用于液相也可用于气相的荧光传感薄膜材料方面的研究工作.     

多元线性模型计算基于荧光猝灭原理的膜传感器对分析物的响 …

根据基于荧光猝灭原理的化学传感膜的结构特征和发光机理,推导并提出量化作用于膜传感器的多种荧光猝灭原因的多元线性模型。结合三杯法,该模型可简便地求出反映不同荧光猝灭机理的特征参数。通过建立的数学模型,测定并计算了芘丁酸膜传感器对应于呋喃妥因等２３种药物多种荧光猝灭因素的响应数据和响应参数。结果表明,传感膜对分析物的响应特征往往能得到主要猝灭因素响应模型的近似反映,这为基于荧光猝灭原理的化学传感器定量     

WO3基气敏传感器*

气敏传感器已在生物、化学、航空、军事等领域获得了广泛的应用。鉴于WO₃基气敏传感器是检测H₂S、NO_x、O₃和NH₃等气体最有前景的新型氧化物气敏传感器之一,本文以不同的敏感气体为分类依据系统阐述了近年来WO₃基气敏传感器的研究进展,详细探讨了制备方法及贵金属掺杂对上述各种气体气敏性能的影响,并指出了目前WO₃基气敏传感器在研究过程中存在的问题。     

桥连氧化钨纳米线的可控合成及气敏性质

The rapid development of industrialization has resulted in severe environmental problems. A comprehensive assessment of air quality is urgently required all around the world. Among various technologies used in gas molecule detection, including Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, mass spectroscopy (MS), electrochemical sensors, and metal oxide semiconductor (MOS) gas sensors, MOS gas sensors possess the advantages of small dimension, low power consumption, high sensitivity, low production cost, and excellent silicon chip compatibility. MOS sensors hold great promise for future Internet of Things (IoT) sensors, which will have a profound impact on indoor and outdoor air quality monitoring. The development of nanotechnology has significantly enhanced the development of MOS gas sensors. Among various nanostructures like nanoparticles, nanosheets and nanowires, the emergence of quasi-one-dimensional (q1D) nanowires/nanorods/nanofibers, with unique q1D geometry (facilitating fast carrier transport) and large surface-to-volume ratio, potentially act as ideal sensing channels for MOS sensors with extremely small dimension, and good stability and sensitivity. These structures have thus been the focus of extensive research. Among the various MOS nanomaterials available, tungsten oxide (WO_3-x, 0 ≤ x < 1) nanowires feature the characteristic properties (multiple oxidation states, rich substoichiometric oxides with distinct properties, photo/electrochromism, (photo)catalytic properties, etc.), and unique q1D geometry (single-crystalline pathway for fast carrier transport, large surface-to-volume ratio, etc.). WO_3-x nanowires have broad applications in smart windows, energy conversation & storage, and gas sensing devices, and have thus become a focus of attention. In this paper, the fundamental properties of tungsten oxide, synthesis methods and growth mechanism of tungsten oxide nanowires are reviewed. Among various (vapor-liquid-solid (VLS), vapor-solid (VS) and thermal oxidation) growth methods, the thermal oxidation method enables an in situ integration of WO_3-x nanowires on predefined electrodes (so-called bridged nanowire devices) via the oxidation of lithographically patterned W film at relatively low growth temperature (~500 ℃) because of interfacial strain, defects and oxygen on the surface of the W film. The novel bridged nanowire-based sensor devices outperform traditional lateral nanowire devices in terms of larger exposure area, low power consumption via self-heating, and greater convenience in device processing. Recent progress in bridged WO_3-x nanowire devices and sensitive NO_x molecule detection under low power consumption have also been reviewed. Power consumption of as low as a few milliwatts was achieved, and the detection limit of NO₂ was reduced to 0.3 ppb (1 ppb = 1 × 10^-9, volume fraction). In situ formed bridged WO_3-x nanowire devices potentially satisfy the strict requirements of IoT sensors (small dimension, low power consumption, high integration, low cost, high sensitivity, and selectivity), and hold great promises for future IoT sensors.     

A dansyl-based fluorescent film: Preparation and sensitive detection of nitroaromatics in aqueous phase

A novel fluorescent film sensor for the detection of nitroaromatics in aqueous phase has been developed via chemical immobilization of dansyl chromophores on an epoxy-terminated self-assembled monolayer on glass slide surfaces. Chemical attachment of the chromophore on the substrate surface endows the present film a satisfying stability and avoids the leaching of the chromophores. Increase in the length of the spacer connecting the sensing element and the substrate results in a dramatic improvement in the performance of the film compared to those with similar structures. Fluorescence quenching experiments demonstrates that in aqueous medium, the emission of the film is more sensitive to nitrobenzene (NB) than to other nitroaromatics, including 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, p-chloronitrobenzene, m-dinitrobenzene, p-dinitrobenzene, and o-chloronitrobenzene, etc. This exceptional result has been rationalized by considering the possible hindrance effect induced by the compact conformation of the long flexible spacer. It is also demonstrated that the NB quenching is static in nature, and the response of the film to NB is fast and reversible.     

Recent advances of multidimensional sensing: from design to applications

Recently, multidimensional(or multi-channel) sensing methodology has attracted broad attention in the field of analytical chemistry due to its fascinating merits. A variety of multidimensional sensors based on sensor arrays, lab-on-a-molecule/nanoparticle and smart chip strategies have been designed to differentiate chemical structure and property similar analytes and complex samples. Pattern recognition algorithms are usually used and allow these sensors to fulfill such proposes. In this review,the recent advances of multidimensional sensor devices were firstly summarized, and particularly focused on their design strategies and applications in monitoring of biological active molecules, biomarkers, microbes, foods and beverages, etc. Then,some limitations and possible solutions of multidimensional sensors were discussed. And finally, potential applications of this technique in the future were proposed. This review would help the readers who are interested in multidimensional sensing methodology to understand the research progresses and trends.     

新型量子点基分子印迹荧光传感器在快速检测中的应用

作为一种新型荧光纳米材料,量子点具有十分优异的光学特性,是分析化学、生物科学、医学等领域研究的热点标记材料。分子印迹聚合物是能够进行特异性识别和选择性吸附的“仿生”材料,它易于制备且具有较好的重现性和稳定性,因而分子印迹技术已成为具有广阔应用前景的识别技术。量子点基分子印迹荧光传感器结合了量子点和分子印迹技术的优势,由于其高选择性和高灵敏度,在环境监测、食品检测、生物分析等领域得到快速发展。但该传感器在应用中也还存在亲水性不足、识别单一、便携性不足等问题。该文引用了近5年来发表在American Chemical Society、Elsevier等数据库约20篇相关文献,对量子点基分子印迹荧光传感器的构建及该传感器在快速检测分析痕量物质中的应用进展进行了综述。首先根据荧光光谱图中发射峰个数的不同分别介绍了3种量子点基分子印迹荧光传感器的类型及相关识别机理,其次根据待测物的不同归纳介绍了近五年来该传感器在离子、有机小分子、生物大分子等检测分析中的最新研究进展,最后对当前该传感器在制备及应用中仍存在的问题进行了总结并对其发展趋势进行了展望。     

共轭聚合物荧光传感器的研究进展

共轭聚合物具有共轭分子导线结构,局部微扰在整个聚合物分子链甚至整个聚合物体系内即能得到放大利用,这一性质决定了其具有检测超低含量待测物的能力,且表现出强于小分子荧光传感器的灵敏度.本文概述了荧光共轭聚合物的传感机理,并举例介绍了近年报道的以共轭聚合物为基础的荧光传感器在检测离子及有机小分子方面的应用.     

Fast and Selective Luminescent Sensing by Langmuir–Schaeffer Films Based on Controlled Assembly of Perylene Bisimide Modified with A Cyclometalated AuIII Complex

Condensed films of functional luminophores dominated by the magnitude and dimensionality of the intermolecular interactions play important roles in sensing performance. However, controlling the molecular assembly and regulating photophysical properties remain challenging. In this study, a new luminophore, ortho-PBI-Au, was synthesized by anchoring a cyclometalated alkynyl-gold(III) unit at the ortho-position of perylene bisimide. An unprecedented T-type packing model driven by weak Au-π interaction and Au−H bonds was observed, laying foundation for striking properties of the luminophore. Controlled assembly of ortho-PBI-Au at the air-water interface, realized using the classical Langmuir–Schaeffer technique, afforded the obtained luminescent films with different packing structures. With an optimized film, sensitive, selective, and rapid detection of a hazardous new psychoactive substance, phenylethylamine (PEA), was achieved. The detection limit, response time, and recovery time were <4 ppb, <1 s, and <5 s, respectively, surpassing the performance of the PEA sensors known thus far. The relationship between the characters of films and the sensing performance was systematically examined by grey relational analysis (GRA). The present study suggests that designing novel molecular aggregation with definite adlayer structure is a crucial strategy to enhance the sensing performance, which could be favorable for the film-based fluorescent sensors.     

过渡金属催化的酰胺C-N键活化

过渡金属催化的酰胺C-N键活化已成为有机化学和金属有机化学热门的研究领域之一。酰胺中羰基C-N键的切断可分为5种不同模式:1)氧化加成反应;2)形成季铵盐后的酰基转移反应;3)质子解反应;4)氢化反应;5)脱羧反应。而酰胺非羰基C-N键的切断可分为4种不同模式:1)氧化加成反应;2)亲核取代反应;3)形成亚胺或亚胺盐;4)β-氨基消除反应。本文综述了近年来过渡金属催化的酰胺中羰基C-N键和非羰基C-N键的不同切断模式。     

Fluorescent chemodosimeters using "mild" chemical events for the detection of small anions and cations in biological and environmental media

Mild chemical processes of various analytes and detection methods involving revolutionary strategies in the fields of analytical chemistry, biology and environmental sciences have been extensively developed. This critical review focuses on representative examples of mild chemical processes that can be used in fluorescent chemodosimeters for ion sensing (anions and cations). A systematisation according to the type of reaction mechanism is established. Numerous examples including extensions combined with catalytic and material sciences applicable in fluorescence imaging and water treatment are also discussed (151 references).     

Preparation and characterization of implantable sensors with nitric oxide release coatings

The widespread use of miniaturized chemical sensors to monitor clinically important analytes such as PO₂, PCO₂, pH, electrolytes, glucose and lactate in a continuous, real-time manner has been seriously hindered by the erratic analytical results often obtained when such devices are implanted in vivo. One major factor that has influenced the analytical performance of indwelling sensors is the biological response they elicit when in contact with blood or tissue (e.g. thrombus formation on the device surface, inflammatory response, encapsulation, etc.). Nitric oxide (NO) has been shown to be a potent inhibitor of platelet adhesion and activation as well as a promoter of wound healing in tissue. Herein, we review recent work aimed at the development of hydrophobic NO-releasing polymers that can be employed to coat catheter-type amperometric oxygen sensors without interfering with the analytical performance of these devices. Such modified sensors are shown to exhibit greatly enhanced hemocompatibility and improved analytical performance when implanted within porcine carotid and femoral arteries for up to 16 h. Further, results from preliminary studies also demonstrate that prototype fluorescent oxygen sensors, catheter-style potentiometric carbon dioxide sensors and subcutaneous needle-type enzyme-based amperometric glucose sensors can also be fabricated with new NO-release outer coatings without compromising the analytical response characteristics of these devices. The NO-release strategy may provide a solution to the lingering biocompatibility problems encountered when miniature chemical sensors are implanted in vivo.     

Membrane-based microextraction techniques in analytical chemistry: A review

The use of membrane-based sample preparation techniques in analytical chemistry has gained growing attention from the scientific community since the development of miniaturized sample preparation procedures in the 1990s. The use of membranes makes the microextraction procedures more stable, allowing the determination of analytes in complex and “dirty” samples. This review describes some characteristics of classical membrane-based microextraction techniques (membrane-protected solid-phase microextraction, hollow-fiber liquid-phase microextraction and hollow-fiber renewal liquid membrane) as well as some alternative configurations (thin film and electromembrane extraction) used successfully for the determination of different analytes in a large variety of matrices, some critical points regarding each technique are highlighted.