本文選題：石墨相C_3N_4 + 氧化石墨烯�。� 參考：《華中科技大學(xué)》2016年博士論文

【摘要】：光電化學(xué)傳感是基于光電轉(zhuǎn)換而發(fā)展起來的一種新型分析方法,因具有裝置簡單、價(jià)格便宜及靈敏度高等優(yōu)勢,而被廣泛用于各種物質(zhì)的分析檢測。光電化學(xué)核酸適配體傳感器是以適配體為特異性識(shí)別元素所構(gòu)建的具有高選擇性的光電化學(xué)傳感器,其中光電活性材料是傳感器核心組成部件,其光電轉(zhuǎn)換效率對(duì)傳感器的響應(yīng)性能有很大的影響,因此,開發(fā)具有高光電轉(zhuǎn)換效率的光電活性材料是發(fā)展此類高性能傳感器的有效途徑之一。另一方面,抗生素濫用問題日益嚴(yán)峻：抗生素濫用不僅導(dǎo)致其對(duì)水體及土壤產(chǎn)生嚴(yán)重的危害,例如破壞生態(tài)系統(tǒng)及產(chǎn)生“超級(jí)細(xì)菌”；而且,其對(duì)人體也產(chǎn)生各種危害,如使人體產(chǎn)生耐藥性、損害人體器官和產(chǎn)生各種過敏反應(yīng)或變態(tài)反應(yīng)等。因此,發(fā)展快速、準(zhǔn)確的抗生素殘留物檢測方法具有重要的意義。本論文在開發(fā)幾種具有高光電活性碳材料基礎(chǔ)上,結(jié)合核酸適配體,發(fā)展了多種高性能的光電化學(xué)核酸適配體傳感器,用于抗生素的高靈敏度、高選擇性檢測,主要研究內(nèi)容如下：(1)研制在水中有良好分散性的石墨相氮化碳(w-g-C3N4)和氧化石墨烯(GO)的復(fù)合材料作為可見光光電活性材料,以與卡拉霉素具有特異性作用的適配體為識(shí)別元件,構(gòu)建了一種用于檢測卡拉霉素的新型光電化學(xué)適配體傳感器。研究結(jié)果發(fā)現(xiàn),適量的GO摻雜能有效地提升w-g-C3N4的可見光光電流響應(yīng),有利于構(gòu)建高靈敏光電化學(xué)傳感器；而且,GO/w-g-C3N4擁有大的比表面積和π-共軛結(jié)構(gòu),可與適配體通過π-π堆砌作用與其結(jié)合固定在傳感器表面,為適配體的固定提供了優(yōu)異的平臺(tái)；當(dāng)待測液中有卡拉霉素時(shí),傳感器上的適配體可捕獲卡拉霉素分子,使光電流得到提升,在優(yōu)化條件下,傳感器的光響應(yīng)電流與卡拉霉素濃度在1nM～230nM范圍為存在線性關(guān)系,檢測限為0.2 nM；此外,該傳感器具有很高的選擇性、良好的重現(xiàn)性和穩(wěn)定性。這些研究結(jié)果表明,GO/w-g-C3N4復(fù)合材料與適配體組合可成功地用于構(gòu)建高性能光電化學(xué)適配體傳感器。(2)用一步水熱法制備氮摻雜石墨烯量子點(diǎn)(N-GQDs)作為傳感器的核心光電轉(zhuǎn)換材料,利用無標(biāo)記的核酸適配體作為生物識(shí)別元件,構(gòu)建用于檢測氯霉素的光電化學(xué)適配體傳感器。透射電鏡表征顯示,所制備的N-GQDs以2.14 nm平均粒徑窄尺寸分布；X射線光電子能譜儀和紅外光譜分析表明氮原子已成功地?fù)诫s進(jìn)了GQDs；紫外-可見吸收光譜測試結(jié)果表明,氮摻雜能顯著提升GQDs在可見光區(qū)的吸收,從而有效地提升了GQDs的光電活性；另一方面,N-GQDs的π-共軛結(jié)構(gòu)可通過π-π堆砌作用與適配體固定結(jié)合。基于這種適配體與N-GQDs構(gòu)建的傳感器對(duì)不同濃度的氯霉素有良好的光電響應(yīng)性能,線性響應(yīng)范圍為10 nM～250 nM,檢測限為3.1 nM。而且,傳感器具有高靈敏度、高選擇性的特點(diǎn),已成功地應(yīng)用于實(shí)際樣品中氯霉素的檢測。(3)制備了g-C3N4與CdS量子點(diǎn)(CdS QDs)的復(fù)合光電材料,用于構(gòu)建四環(huán)素檢測的光電化學(xué)適配體傳感器。對(duì)于所研制的g-C3N4-CdS QDs復(fù)合材料,表面形貌觀察表明,平均尺寸約4 nm的CdS QDs以緊密接觸方式分布在g-C3N4表面上；紫外-可見漫反射光譜顯示,g-C3N4在可見光區(qū)的吸收因CdS QDs的耦合而顯著增強(qiáng)；與單組分光電材料相比,g-C3N4-CdS QDs復(fù)合材料具有較高的光電化學(xué)活性。將此g-C3N4-CdS QDs復(fù)合材料用作傳感器組件,并在其上固定適配體作生物識(shí)別元件,構(gòu)建了一種用于四環(huán)素檢測的可見光驅(qū)動(dòng)的光電化學(xué)適配體傳感器,對(duì)四環(huán)素的線性響應(yīng)范圍為10 nM-250 nM,檢測限為5.3 nM。本研究成功地證實(shí),經(jīng)CdS QDs敏化后的g-C3N4可用于發(fā)展高靈敏度、高選擇性的光電化學(xué)傳感器、是一種極具應(yīng)用前景的可見光電活性復(fù)合納米材料。
[Abstract]:Photoelectrochemical sensing is a new analytical method developed based on photoelectric conversion. It is widely used for analysis and detection of various substances because of its simple device, cheap price and high sensitivity. Photoelectrochemical nucleic acid aptamer sensor is a highly selective light based on aptamer as a specific identification element. The photoelectric active material is the core component of the sensor, and the photoelectric conversion efficiency has a great influence on the response performance of the sensor. Therefore, it is one of the effective paths to develop the high performance photoelectric active material with high photoelectric conversion efficiency. On the other hand, the problem of antibiotic abuse is becoming more and more important. Severe: the abuse of antibiotics not only causes serious harm to water and soil, such as destroying the ecosystem and producing "superbacteria", but also produces various hazards to the human body, such as the resistance to the human body, the damage of human organs and the production of various allergic reactions or allergies. On the basis of developing several high optoelectronic active carbon materials and combining with nucleic acid aptamers, a variety of high-performance photochemical nucleic acid aptamers are developed in this paper, which are used for high sensitivity and high selective detection of antibiotics. The main contents are as follows: (1) development in water A well dispersed graphite phase carbon nitride (w-g-C3N4) and graphene oxide (GO) composite was used as a visible light photoactive material, and a novel photophotochemical aptamer sensor used for the detection of Cara mycin was constructed with a specific ligand with Cara mycin. The results showed that a proper amount of GO was doped. It is beneficial to improve the visible light current response of w-g-C3N4, which is beneficial to the construction of highly sensitive photochemical sensors. Moreover, GO/w-g-C3N4 has a large specific surface area and a PI conjugated structure, which can be combined with the aptamers by pion pion stacking and immobilized on the surface of the sensor, and provides an excellent platform for the fixation of the adapter. In the case of Cara mycin, the aptamers on the sensor can capture the Cara mycin molecule and improve the photocurrent. Under optimal conditions, the optical response current of the sensor is linear with the range of 1nM to 230nM in the range of 1nM to 230nM, and the detection limit is 0.2 nM; in addition, the sensor has high selectivity, good reproducibility and stability. The results show that the combination of GO/w-g-C3N4 composites and aptamers can be successfully used in the construction of high performance photochemical aptamers. (2) the preparation of nitrogen doped graphene quantum dots (N-GQDs) by one step hydrothermal method as the core photoelectric conversion material of the sensor, and the use of unlabeled aptamers as a biometric element. The photoelectrochemical aptamer sensor used for the detection of chloramphenicol was constructed. The transmission electron microscope showed that the prepared N-GQDs was distributed in a narrow size of 2.14 nm, and the X ray photoelectron spectroscopy and infrared spectroscopy showed that the nitrogen atoms had been successfully doped into the GQDs; the UV visible absorption spectra showed that the nitrogen doping could be significant. The absorption of GQDs in the visible region is enhanced and the photoactivity of GQDs is effectively enhanced; on the other hand, the PI conjugated structure of N-GQDs can be immobilized with the aptamer by the pion pion stack. The sensor based on this aptamer and N-GQDs has good photoelectric response to chloramphenicol of different concentrations, and the linear response range is 10. NM ~ 250 nM, with a detection limit of 3.1 nM. and the sensor has high sensitivity and high selectivity, has been successfully applied to the detection of chloramphenicol in actual samples. (3) a composite photoelectric material of g-C3N4 and CdS quantum dots (CdS QDs) is prepared for the construction of a photochemical aptamer sensor for tetracycline detection. For the developed g-C3N4-CdS QD The surface morphology of s composites shows that the CdS QDs with an average size of about 4 nm is distributed on the g-C3N4 surface in close contact, and the UV visible diffuse reflectance spectra show that the absorption of g-C3N4 in the visible region is significantly enhanced by the coupling of CdS QDs. Compared with the single component optoelectronic materials, the g-C3N4-CdS QDs composite has a higher photoelectrochemistry. Using this g-C3N4-CdS QDs composite as a sensor component and immobilized the aptamer as a biometric element, a photochemical aptamer sensor driven by visible light for tetracycline detection is constructed. The linear response range to tetracycline is 10 nM-250 nM, and the detection limit of 5.3 nM. is successfully confirmed by Cd. The g-C3N4 sensitized by S QDs can be used for the development of high sensitivity, high selectivity photochemical sensors. It is a promising visible photoactive composite nanomaterial.

【學(xué)位授予單位】：華中科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：O657.1;TP212.2
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本文編號(hào)：1837722