發(fā)布時間：2018-06-18 20:03

  本文選題：光電化學傳感器 + 染料　； 參考：《南京郵電大學》2017年碩士論文

【摘要】：光電化學傳感器是基于物質的光電轉換特性確定待測物濃度的一類檢測裝置。光電化學檢測方法靈敏度高、設備簡單、易于微型化,已經成為一種極具應用潛力的分析方法。以DNA、RNA和蛋白質為檢測對象的光電化學傳感器,激發(fā)單元與檢測單元相分離,在實際檢測過程中可以減弱各種干擾因素,降低背景信號,提高分析檢測的靈敏度和選擇性,應用前景廣泛。對電化學分析法和光電化學分析法進行文獻調研,我們注意到:對光電化學傳感器研究的重點在于電解液中光電轉換傳感識別單元的設計,而光陽極通常固定為一些具有光伏效應的半導體材料,例如氧化鈦、氧化鋅等。以這種方式構筑的光電化學傳感體系在工作狀態(tài)下,存在嚴重的界面阻力,從而對整個光電轉換效率產生影響,特別是傳感檢測選擇性主要依賴于免疫反應,導致了光電化學生物傳感應用受到極大限制。本論文針對此問題,創(chuàng)新性的發(fā)展基于光電化學檢測技術,利用半導體材料的光電特性產生光生電子空穴對,從而形成光誘導電荷轉移的方式實現對光電流進行檢測,可以更高選擇性和靈敏地檢測與該電流相關的生化反應中待測物的濃度。主要研究內容分為以下三個方面:第一,基于染料敏化光電化學太陽能電池的原理,利用具有推-拉電子效應的染料分子在與含巰基化合物反應前后光吸收特性差異造成的光電流變化作為輸出檢測信號,從而實現對半胱氨酸的傳感檢測。實驗證明,本實驗整個過程中不再局限于電極界面過程,能在多種復雜環(huán)境中實現特定生物分子如半胱氨酸等含巰基的生物大分子的高靈敏、選擇性、定量檢測,應用前景巨大。第二,將光電化學傳感器與DNA生物傳感器相互結合,通過空間限制構造PEC生物傳感器實現對mi-RNA的檢測。利用ITO/TiO_2/Au為基底,構建穩(wěn)定基底。將光電化學測試與DNA生物傳感器結合起來,同時Au納米顆粒與P-DNA的連接,起到對信號的放大作用,實驗結果得到mi-RNA的檢測限為0.12 fM。第三,通過簡單水熱法制備出的石墨烯/二硫化鉬的光陽極復合材料,最大創(chuàng)新點在于充分地利用二硫化鉬與石墨烯層狀結構,石墨烯基復合材料具有制備簡便,結構新穎、穩(wěn)定,比電容值高等優(yōu)點。而石墨烯具有超高表面積和導電率,應用于光電化學傳感器的光陽極中,為進一步拓展應用提供了基礎�？傮w而言,我們分別對光陽極、電極基底材料、檢測對象三個方面進行了初步分析和研究,較深入的對課題設計思想進行驗證,初步研究結果表明,我們對光陽極改造的光電化學傳感器構筑方法具有創(chuàng)新性和可行性,為此后進行相關研究奠定理論和實踐基礎。
[Abstract]:Photoelectric chemical sensor is a kind of measuring device which is based on the photoelectric conversion characteristics of matter to determine the concentration of the object to be measured. Photoelectric chemical detection method with high sensitivity, simple equipment and easy miniaturization has become a very potential analytical method. The photochemical sensor with DNA RNA and protein as the detection object, the excitation unit is separated from the detection unit, which can attenuate all kinds of interference factors, reduce the background signal, and improve the sensitivity and selectivity of analysis and detection. The application prospect is wide. Through the literature research on electrochemical analysis and photochemical analysis, we noticed that the focus of the research on photoelectrochemical sensor is the design of photoelectric conversion sensor identification unit in electrolyte. Photoanodes are usually fixed as photovoltaic semiconductor materials, such as titanium oxide, zinc oxide and so on. The photoelectric chemical sensing system constructed in this way has serious interfacial resistance in the working state, which has an impact on the whole photoelectric conversion efficiency, especially the selectivity of the sensing detection mainly depends on the immune response. As a result, the application of photochemical biosensor is greatly restricted. Aiming at this problem, the innovative development of this paper is based on photochemical detection technology, using the photoelectric properties of semiconductor materials to generate photogenerated electron hole pairs, thus the photoinduced charge transfer method is formed to detect photocurrent. It is more selective and sensitive to detect the concentration of the substance to be tested in the biochemical reaction associated with the current. The main research contents are as follows: first, based on the principle of dye sensitized photochemical solar cells, The photocurrent changes caused by the difference of photoabsorption characteristics of dye molecules with push-pull electron effect before and after reaction with sulfhydryl compounds are used as the output detection signals to realize the sensing detection of cysteine. The experiments show that the whole process is no longer confined to the electrode interface process, and it can be used to detect specific biomolecules such as cysteine, in high sensitivity, selectivity and quantification in many complex environments. The application prospect is great. Secondly, PEC biosensor is constructed to detect mi-RNA by combining photochemical sensor with DNA biosensor. The stable substrate is constructed by using ITO / TiO- 2 / au as the substrate. The combination of photochemical test and DNA biosensor and the connection of au nanoparticles with P-DNA can amplify the signal. The detection limit of mi-RNA is 0.12 fM. Third, the photoanode composites of graphene / molybdenum disulfide prepared by simple hydrothermal method have the greatest innovation in making full use of the layered structure of molybdenum disulfide and graphene. Stable, higher than the value of capacitance and other advantages. Graphene has high surface area and conductivity and is used in photoanode of photochemical sensor, which provides a basis for further development of application. In general, we have carried on the preliminary analysis and the research to the photoanode, the electrode substrate material, the inspection object separately, has carried on the confirmation to the topic design idea in depth, the preliminary research result indicated, We are innovative and feasible for the construction of photoanode photochemical sensor, which will lay a theoretical and practical foundation for the related research in the future.
【學位授予單位】：南京郵電大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TP212.2

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本文編號：2036699