【作者】 张涛；

【导师】 金钦汉；

【作者基本信息】 吉林大学 ， 分析化学， 2007， 博士

【摘要】 本论文分两部分。在第一部分中,首先对荧光共轭聚合物作了简单的概述,并且详细介绍了荧光共轭聚合物的信号放大机理及其在化学传感领域的应用。接下来,着重阐述了本研究工作的主要内容:发展了一种新的、未见文献报道过的制备水溶性共轭聚合物PPESO3的简便合成路线,不仅简化了反应步骤,还成功避免了BBr3的使用,大大降低了制备过程的难度和危险性,为PPESO3和具有类似结构的PPE类荧光共轭聚合物的制备以及更广泛地对其进行研究和应用提供了便利条件;在此基础上,开发了基于荧光共轭聚合物超猝灭的新型过氧化氢和甲醛传感器,该法具有试剂少、结构简单、响应速度快以及高灵敏高等优点,对于室内空气中甲醛的快速检测以及尿糖分析都有重要的应用价值;此外,还对PPESO3与蛋白的非特异性结合作用进行了研究,并由此发展了一种通用的测量蛋白酶活性的新方法。在第二部分中,首先评述了近红外光谱分析技术的发展概况,指出了研制便携式近红外粮食成分快速分析仪的意义。接下来,详细阐述了本论文所承担的科研项目――《快速粮食成分光电分析仪研制开发》的研发过程:对无信息变量消去法进行改进,并用于玉米样品吸收光谱的波长筛选;参与研制了一台采用全固态设计的便携式近红外玉米成分快速分析仪,样品不需要前处理,一次测量可以同时获得玉米中多种组分的含量,并且测量速度快,准确度高,重复性好,可广泛用于玉米收购、仓储及深加工等领域,进行水分、总蛋白、粗脂肪和淀粉的现场测定。更多还原

【Abstract】 Part A Preparation and application of fluorescent conjugated polymersConjugated polymers （CPs）, a kind of very important organic semi-conductive luminescent materials, have gained extensive studies since 1977, with the discovery that polyacetylene’s conductivity could be greatly enhanced by doping. Especially in the last two decades, conjugated polymers have received broad applications in the area of photoelectric devices such as CP-based LED, plastic lasers and field-effect transistor, etc, because of their superior properties in luminescence, electronics and magnetics. However, the research on using fluorescent conjugated polymers （FCPs） as sensing materials just began in the mid of 1990s. Due to the unique molecular-wire effect of FCPs, the fluorescence responses could be greatly amplified without changing the association constants with specific analytes, which provides good opportunities to design high sensitive chemo-sensors. Therefore, in recent years, FCP-based bio- and chemo- sensors have attracted increasing attentions in the detection of organic molecules, metal ions and bio-molecules, and gradually became one of the hot topics.For the applications in sensing, FCPs with ionic side-groups （also known as conjugated polyelectrolytes） have great superiorities when compared to traditional conjugated polymers that could solve in organic solvents: On one hand, the water-solubility makes them more suitable in bio-systems; And on the other hand, the existence of cations or anions provides an effective means of interaction with analytes in designing sensors; Also the sensitivity to quenchers with opposite charges is further increased to a large extent. In our work, the PPE-type conjugated polyelectrolytes have been studied in details with focuses on preparation and their applications in sensing. The main contents include:The progress, category and electronic structures of conjugated polymers are introduced in the first chapter. Also, the mechanism of signal amplification and the application of FCPs in sensing are reviewed in detail as well.In Chapter two, a novel facile synthetic route for the preparation of PPESO3 was developed. Starting from hydroquinone, only three steps were required: Under basic conditions, sulfonated receptors were installed via 1,3-propanesultone, followed by the electrophilic substitution of iodine in a mixture of glacial acetic acid and water, and PPESO3 was obtained by palladium-catalyzed cross-coupled reaction with 1,4-diethynylbenzene. Compared with the scheme reported by Tan et al., this new route is much simpler and more effective. Not only the procedure is simplified, but most importantly, the preparing difficulty, complexity and danger were greatly reduced by avoiding the use of BBr3, which will be certainly beneficial to the preparation and application of PPESO3 and other PPEs with similar structures.Chapter three to Chapter five emphasized on the application studies of PPESO3. In Chapter three, the optical property and aggregation in water of PPESO3 were discussed. Further, interactions of PPESO3 with metal ions and surfactants were investigated as well. And the results indicated that most metal ions would not interfere with PPESO₃ applied in sensing when their concentration is below 10μM. Moreover, the polymer’s fluorescence could be effectively quenched by Fe³⁺, while Fe²⁺ had almost no effect. This phenomenon provides feasibility to design high sensitive sensors based on the redox of Fe²⁺/Fe³⁺. Therefore, in Chapter four, by making use of the oxidation of Fe²⁺, sensors for formaldehyde and peroxide based on the superquenching of PPESO₃ have been developed. These sensors featuring less reagents, simple structure and high sensitivity, are valuable for the detection of formaldehyde in room environment and urine glucose, respectively. In the last chapter, a general method for the detection of protease activity is discussed. BSA could greatly enhance the fluorescence of PPESO3 due to its surfactant effects, and concomitant with a significant blue-shift. However, once BSA is hydrolyzed by protease the system fluorescence would restore. By this means, one can easily monitor the activity of protease, which will certainly facilitate the discovery of drugs based on enzyme inhibitor.Part B Study on the development of fast portable NIR corn component analyzerNear infrared spectroscopy （NIRS） is an analytical technique that has progressed very rapidly in recent years. Due to its many merits, such as rapid, real-time or even on-line detection, NIRS has been widely used in agriculture, food, petroleum and pharmacy. Especially in the process of foodstuff purchasing, storage or measurement, the advantages such as fast speed and no sample pretreatment of NIRS have made it a more and more important analytical tool. As the substantial foundation, NIR instruments have also gained great developments, in which the miniature specific NIR analyzer based on filters design has obvious priorities in the detection of corn components on site.In our research, a fast portable NIR corn component analyzer based on filters has been developed. The development process and instrumental performance of the newly developed analyzer will be described in this part. First, in Chapter one, the NIR Spectroscopy was reviewed in detail, including its development, characteristics, instruments, commonly used chemometrics methods and main application fields.In Chapter two, some kinds of the algorithms for variable selection were discussed, and the method Uninformative Variables Elimination （UVE）, was chosen to pick out wavelengths from corn NIR spectrum. These results provided good supports for the designing of filter based fast portable NIR corn component analyzer.Chapter three was the core content of Part B, in which the research project of this NIR corn component analyzer was fully presented: The LED array composed of ultra-bright NIR LEDs and narrow-band interference filters, together with a silicon photo-diode detector constituted the optical system. In order to improve the signal intensity and repeatability, unique optical design, silicon photo-diode with large active area and series-wound LED technique were adopted. In the controlling circuit system, the motivation of LED, photo-electric conversion, grounding and time sequence design were optimized, which greatly improved the instrumental performance. For dada processing, PLS algorithm, temperature compensation technique and multiple scatter calibration were combined to construct a robust model. And in the end of this chapter, the performance of the newly developed analyzer, including accuracy, repeatability and stability toward temperature changes, were examined systematically. And the results were satisfactory.更多还原