| Nanomaterialis between0.1and100nrn in size. Nanomaterials have unique physical and chemical properties due to quantum confinement and exceedingly large surface to volume ratio. They have a superior performance to the materials now existing. Metal oxide nanomaterials have been a hot topic in recent years, which have extensive applications and potential value in optics, electrics, mechanics, and magnetics,Chemiluminescence (CL) is known as a powerful analytical technique that promises high sensitivity, wide linear range and simple instrumentation. The emergence of noble metal nanoparticles has expanded the application range of CL studies. However, there are only a few reports on the CL of metal oxide nanomaterials. In our work, we systematically studied a variety of metal oxide nanoparticles, and we found that they exhibit high specific catalytic effects on the CL reaction of the luminol-H2O2system in alkaline solution compared with other common catalysts. In this system, luminol with very low concentration can get excellent experimental result with higher selectivity than other luminol system. We have developed a novel CL sensor array to determine Triacetone Triperoxid (TATP) in the suspected items. We have developed a novel CL method to determine the removal rate constant of H2O2by human erythrocytes. We have developed a novel CL approch to determine trace quantities of H2O2in exhaled breath condensate (EBC) where it is a mediator of oxidative stress and a promising biomarker for diagnosing. We also have developed bifunctional CL probe arrays and sensors to determine a variety of biochemical substances, which were based on mesoporous nanocomposite material.The application of metal oxide nanomaterials in analysis is summarized in Chapter1. The research work of the dissertation is made up of two sections:(I) The study of metal oxide nanomaterials used as catalyter in luminol-H2O2CL system and its applicationMetal oxide nanomaterials (Co3O4, Cr2O3, CeO2, NiO, a-Fe2O3,CuO, Y2O3, Nd2O3, possess more excellent catalysis in H2O2CL system than previously reported (such as Co2+, Cu2+, Cr3+, HRP and so on). The selectivity CL reaction of luminol-H2O2metal oxide nanomaterials has been proposed.(1) New CL techniques based on metal oxide nanomaterials catalysis for high-throughput determination of the explosive Triacetone Triperoxide at the sceneTATP is a new organic peroxide based explosive, which decomposes via an entropically favorable mechanism to form4gas phase molecules (a10g sample gave250cm3expansion in the trauzl test as compared to300cm3for TNT). TATP is a highly unstable compound. Explosions may occur by friction, impact or temperature changes, especially in solid phase samples. TATP can be dissolved in a variety of solvents to enhance the stability, such as using an ordinary hair gel, shampoo, shower gel, or other liquids and gels. Metal detector, X-ray baggage scanner, and many detection devices that readily detect tradition explosives made of organic nitro and nitrate compounds fail to detect TATP.Here we report on the finding that CeO2nanoparticles are capable of strongly enhancing the CL of the luminol-H2O2system. CeO2nanoparticles can be firmly adsorbed on the96-well plates made of polystyrene to form a very solid sensing membrane. The vapor pressure of TATP is8×10-2Torr at25℃. Its vapor can be absorbed onto suitcases and rapidly hydrolyze into H2O2in wet air. Soaked swabs were used to sample the suspected items (pen, plastic bag, banknotes, paper, card), which may be possible carried on an airplane. Immediately after collection, samples were transferred to10mL centrifuge tubes with5mL ultrapure water, which were then sealed for storage.50μL sample solution and50μL (5×10-5M) luminol were injected into the CL sensor array and readings were acquired. The integrated kinetic curve for each sensor can be obtained within5s. The process is easy to perform. It has been successfully applied to the detection of TATP in the suspected items, which may be possible carried on an airplane.In this paper, we also synthesized Cr2O3nanoparticles (about20nm). Cr2O3nanoparticles were found to greatly enhance the CL intensity of luminol-H2O2system. A reaction mechanism was discussed. The novel CL method also has been successfully applied to the detection of TATP at the scene. Especially, some organic hydroperoxides such as carbamide peroxide, tert-butyl hydroperoxide and cumene hydroperoxide do not interfere with the determination.(2) CL assay for hydrogen peroxide in exhaled breath condensate using Co3O4 nanoparticle-based catalysisWe systematically studied the nanoparticles-luminol-H2O2CL system. The catalytic activity of three nanoparticles (Co3O4, NiO, a-Fe2O3,) were investigated using microarray method. The CL method based on the use of the Co3O4nanoparticles is ultrasensitive and particularly selective. Under the optimum conditions described above, the linear calibration range prolonged over3orders of magnitude from1.0nm to1000nM. The limit of detection (LOD,3σ) for hydrogen peroxide was0.3n M. A new CL method for the determination of H2O2in exhaled breath condensate (EBC) was built by combining with flow injection technology. The method was successfully applied to the determination of trace quantities of H2O2in EBC where it is a mediator of oxidative stress and a promising biomarker for diagnosing (healthy subjects, rheum subjects, and feverish subjects). Our data suggested that the average H2O2concentration of EBC from feverish subjects was significantly higher than healthy subjects and rheumatic subjects.(3) A CL microarray based on catalysis by CeO2nanoparticles, and its application to determine the rate of removal of hydrogen peroxide by human erythrocytesIt is important that nano-oxide surface defects in the catalytic reactions. CeO2nanoparticles vacancies present on the surface. It has excellent oxygen storage capacity. Hydrophilic CeO2nanoparticles were also shown highly active and selective for the luminol-H2O2system. H2O2is a normal metabolite in living cells. It is important for cells to remove hydrogen peroxide due to superfluous H2O2may oxidize cellular components. Tight control of cellular H2O2levels is important to avoid oxidative damage of cellular components and to maintain the regulation of various cell responses. The microarray CL method based on the use of the CeO2nanoparticles is ultrasensitive and particularly selective. It has been successfully applied to the measurement of removal rate constant of hydrogen peroxide by human erythrocytes.(II) The study of metal oxide nanomaterials used as bifunctional CL probe arrays and sensors and its application in analysis a variety of biochemical substances.Mesoporous material is a material containing pores with diameters between2and50nm. Mesoporous metal oxide nanoparticles have good monodisperse pore rules, adjustable aperture, large surface area, good thermal stability and other characteristics. Mesoporous metal material with over1000m2.g-1surface area and pore structures can provide the target-receptor a lot sites and sufficient interface to help adsorbed target and enhance the concentration of the target. Mesoporous material is suitable for immobilization of various substances, such as drugs, enzymes and antibodies. Our research found that mesoporous metal oxide nanomaterial itself has an excellent catalytic effect on the CL reactions. The novel bifunctional CL probe array has been applied to the high-throughput determination of a variety of biochemical substances.(1) A novel bifunctional CL probe array for the determination of glucose in human serum.A new CL probe array assay approach was first developed. The new CL probe array was based on Co3O4-SiO2mesoporous nanocomposite material, which not only has an excellent catalytic effect on the luminol-H2O2CL reaction in alkaline medium but also can be used for the immobilization of enzymes. As a model, the novel bifunctional CL probe array has been applied to the high-throughput determination of glucose in human. The linear range of the glucose concentration was3-90μM and the detection limit was0.36μM.(2) A novel bifunctional CL probe array for the determination of lactose in milk was established.In our work, we further explored the mesoporous Co3O4-SiO2bifunctional CL probe array. The new type CL probe array was also based on enzyme mimics of Co3O4-SiO2mesoporous nanocomposite material, which not only have an excellent catalytic effect on the luminol-H2O2CL reaction in alkaline medium but also can be used for the immobilization of enzymes.β-galactosidase and glucose oxidase were selected as a model for enzyme assays to demonstrate the applicability of Co3O4-SiO2mesoporous nanocomposite material in multienzyme immobilization. It is different from the traditional probe. The linear range of the lactose concentration was3.0×10-7to1.0×10-5g·mL-1and the detection limit was6.9×10-8g·mL-1. It has been successfully applied to determine lactose in milk.(3)A novel CL sensor array combined with mesoporous enzyme reactor for high-throughput determination of glucose in human serumA novel enzyme reactor was prepared by calcium alginate fiber and amino modified nanosized mesoporous silica (CAF-AMNMS) as support. Combination the adsorption of enzyme on AMNMS with the cage effect of the polymer greatly increases catalytic activity and stability of immobilized enzyme. It was showed that the lifetime, stability and catalytic activity of enzyme reactor greatly improved by incorporating AMS into CAF to efficiently encapsulate enzyme. Glucose oxidase ((pI=4.0)) was chosen as a model enzyme to explore the possibility of CAF-AMNMS as a matrix for enzyme immobilization in the design of a CL microreactor. The unique sensor array combined with the enzyme reactor has been successfully applied to the high-throughput determination of glucose in human... |
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