【摘要】：光電化學(PEC)生物傳感是將光電化學技術與生物識別相結合而發(fā)展起來的新的傳感方法,該技術背景信號低、靈敏度高、裝置價格低廉。目前,PEC生物傳感已成為生物分析領域中一門重要的分析技術。本論文用不同的光電活性材料構建了高靈敏的PEC生物傳感器件,并實現(xiàn)了對生物分子如半胱氨酸、DNA等靈敏檢測。第一章綜述了PEC傳感技術,對PEC傳感器的基本工作原理及其構建過程進行闡述。另外,針對不同的檢測對象,對PEC傳感器進行了分類,最后介紹了一下本論文的主要工作。第二章制備石墨烯-硫化鎘摻錳納米復合物,并構建了半胱氨酸PEC傳感器。石墨烯比表面積較大,負載更多硫化鎘,而且石墨烯-硫化鎘摻錳納米復合物能夠有效提高光生電子-空穴分離效率,增強光電流。由實驗結果可知,該納米復合物對半胱氨酸具有優(yōu)良的檢測性能。第三章利用無機-有機納米復合物敏化結合λ核酸外切酶(λ-Exo)循環(huán)剪切放大作用,實現(xiàn)對DNA的檢測。在目標DNA存在條件下,互補DNA/目標DNA雙鏈中的互補DNA可被λ-Exo剪切,釋放出目標DNA,其再次與互補DNA雜交,從而起到目標DNA循環(huán)放大的效果。而殘余的互補DNA可以與無機-有機納米復合物標記的探針DNA進行互補,從而實現(xiàn)對電極進行共敏化。這種雙信號放大傳感器的構建,為癌癥DNA的檢測提供了新的超靈敏分析平臺。第四章構建了基于酶循環(huán)剪切、鏈擴增和酶催化反應的信號放大DNA光電傳感器的構建。首先電極上電還原氧化石墨烯,后修飾硫化鎘納米晶以及硫化鋅,然后固定捕獲DNA,在含有目標DNA,發(fā)卡DNA,λ-Exo的溶液中孵育時,循環(huán)剪切反應發(fā)生,輸出的DNA鏈與捕獲DNA互補,隨后在溶液中通過鏈式擴增進一步放大,最后通過生物素-親和素作用連接上ALP酶,進行催化放大。結果表明,構建的PEC傳感器能對目標DNA進行超靈敏檢測。
[Abstract]:Photochemical (PEC) biosensor is a new sensing method which combines photochemical technology with biometric identification. It has low background signal, high sensitivity and low cost. At present, PEC biosensor has become an important analytical technique in the field of biological analysis. In this paper, highly sensitive PEC biosensor devices were constructed using different photoactive materials, and the sensitive detection of biomolecules such as cysteine PEC was realized. In the first chapter, the PEC sensor technology is reviewed, and the basic working principle and construction process of PEC sensor are described. In addition, PEC sensors are classified for different detection objects, and the main work of this thesis is introduced. In chapter 2, graphene-cadmium sulphide-doped manganese nanocomposites were prepared and cysteine PEC sensors were constructed. The specific surface area of graphene is larger and the loading of cadmium sulfide is more. Moreover, the nano-composite of graphene and cadmium sulfide doped with manganese can effectively improve the efficiency of photoelectron hole separation and enhance photocurrent. The experimental results show that the nanocomposite has good detection performance for cysteine. In chapter 3, the detection of DNA was realized by sensitizing the inorganic and organic nanocomposites and lambda nucleic acid exonuclease (位 -Exo) cyclic shearing amplification. Under the condition of the existence of target DNA, the complementary DNA in the double strand of complementary DNA/ DNA can be cut by 位 -Exo, and the target DNA, can be hybridized with complementary DNA again, so that the target DNA can be cyclically amplified. The residual complementary DNA can complement the probe DNA labeled by inorganic-organic nanocomposites, so that the electrode can be co-sensitized. The construction of the dual signal amplification sensor provides a new hypersensitive analysis platform for cancer DNA detection. In chapter 4, the DNA photoelectric sensor based on enzyme cyclic shearing, chain amplification and enzymatic catalytic reaction was constructed. After electroreduction of graphene oxide and modification of cadmium sulfide nanocrystalline and zinc sulfide on the electrode, cyclic shear reaction occurs when DNA, is incubated in a solution containing the target DNA, hairpin DNA, 位 -Exo, and the output DNA chains complement the captured DNA. Then the chain amplification was carried out in the solution, and the ALP enzyme was connected with biotin-avidin to catalyze the amplification. The results show that the constructed PEC sensor can detect the target DNA with hypersensitivity.
【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

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相關碩士學位論文 前2條

1 朱樺;基于半導體納米材料的標記型光電化學免疫傳感[D];南京大學;2016年

2 韓麗;基于不同傳感策略構建的光電化學生物傳感器[D];南京郵電大學;2015年

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本文編號：2223819