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  本文關(guān)鍵詞：基于新型碳納米復(fù)合材料構(gòu)建電致化學(xué)發(fā)光酶生物傳感器的研究　出處：《西南大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 酶生物傳感器 納米復(fù)合材料 電致化學(xué)發(fā)光 魯米諾

【摘要】：電致化學(xué)發(fā)光(Electrochemiluminescence,ECL)是在電極表面施加一定的電壓發(fā)生化學(xué)反應(yīng)從而產(chǎn)生一些特殊的電極產(chǎn)物,這些電極產(chǎn)物之間或者電極產(chǎn)物與體系中某組分之間通過電子傳遞形成激發(fā)態(tài),由激發(fā)態(tài)躍遷返回基態(tài)過程中產(chǎn)生的一種光輻射。它是電化學(xué)方法和化學(xué)發(fā)光方法相結(jié)合形成的一種新型檢測技術(shù),具有靈敏度高、選擇性好、過程易于控制、操作簡單等優(yōu)點。酶生物傳感器是以固定化酶膜為生物識別元件、修飾電極為信號轉(zhuǎn)換器件,因此其不僅具有酶的分子識別功能和選擇催化功能,還具有電極響應(yīng)迅速、易于操作等特點。ECL酶生物傳感器將ECL檢測技術(shù)與酶的高度專一性和高效催化性融合在一起,具有高靈敏度、高選擇性等特點。隨著納米技術(shù)的快速發(fā)展,各種納米材料已被廣泛應(yīng)用于生物傳感器領(lǐng)域,在表現(xiàn)納米材料各種優(yōu)勢性能(如大的比表面積、獨特的電化學(xué)性質(zhì)、好的生物相容性等)的基礎(chǔ)上為生物傳感器的發(fā)展開辟了廣闊的應(yīng)用前景并實現(xiàn)了生物傳感器的高靈敏檢測。其中,碳納米管和石墨烯均具有特殊的物理和化學(xué)性質(zhì),具有良好的導(dǎo)電性和電催化特性,能夠使電子在固定化酶與電極之間進行快速而有效地傳遞。同時,將基于碳納米材料研制的新型納米復(fù)合材料應(yīng)用于酶生物傳感器的構(gòu)建中可為酶的固定提供良好的微環(huán)境,從而保持酶的生物活性。基于以上考慮,本文研制了基于碳納米材料的新型納米復(fù)合材料并構(gòu)建了一系列靈敏的ECL酶生物傳感器,且性能都較以往的酶生物傳感器有很大程度上的提高。本論文主要研究工作如下：1.基于Hemin功能化多壁碳納米管納米復(fù)合材料的電致化學(xué)發(fā)光膽固醇生物傳感器該工作結(jié)合多壁碳納米管(MWCNTs)對過氧化氫(H202)具有電催化氧化活性以及Hemin對H202電化學(xué)氧化從而增強Luminol-H2O2體系的ECL信號的特性,制備了新型的Hemin-MWCNTs納米復(fù)合材料,并將其應(yīng)用于膽固醇的檢測。首先,合成Hemin-MWCNTs納米復(fù)合材料,將其滴涂于預(yù)先處理好的裸玻碳電極表面,待電極在室溫下干燥后再在其表面滴涂膽固醇氧化酶并于4℃孵育若干小時即可。由于Hemin-MWCNTs對H2O2有很好的電催化性能,可增強體系的ECL信號。在最優(yōu)實驗條件下,該傳感器的ECL響應(yīng)與膽固醇濃度在3×10-7～1.2×10-3 mol·L-1范圍內(nèi)呈現(xiàn)良好的線性關(guān)系,檢測限為1×10-7 mol·L-1。此外,該傳感器具有靈敏度高\準確度及穩(wěn)定性好等優(yōu)點。2.基于碳納米管-氧化石墨烯.硫堇-納米金的電致化學(xué)發(fā)光膽固醇生物傳感器首先,碳納米管與氧化石墨烯(GO)以質(zhì)量比為1：1結(jié)合成納米復(fù)合物可展現(xiàn)出良好的電催化活性。其次,某些還原劑(如肼)有毒,因此必須控制用量。由于硫堇(Thionine,Thi)結(jié)構(gòu)中有大量氨基以及GO結(jié)構(gòu)中的大量羥基,可作為一些物質(zhì)(例如氯金酸)的還原劑,還原得到的納米金(AuNPs)對于Luminol - H2O2體系的ECL有極大的增強作用,并且GO作為還原劑還原氯金酸的同時,還可以作為AuNPs的生長模板。基于以上兩點,在未加入其它還原劑的情況下,利用GO和Thi自身的還原性,原位還原氯金酸制備了MWCNTs-GO-Thi-Au納米復(fù)合材料,并將該納米復(fù)合材料應(yīng)用于膽固醇的檢測。由于該納米復(fù)合材料對Luminol - H2O2體系的ECL信號具有放大作用,使得檢測限大大降低。在最優(yōu)實驗條件下,該傳感器呈現(xiàn)了較寬的線性范圍(0.15～828μmol·L-1)和相對較低的檢測限(50nmol·L-1)。結(jié)合納米復(fù)合物以及ECL檢測方法的優(yōu)勢,將本實驗所構(gòu)建的生物傳感器應(yīng)用于臨床生物檢測具有巨大的潛在價值。3.基于生物功能化的AMs-ChO生物復(fù)合材料的電致化學(xué)發(fā)光膽堿生物傳感器由于石墨烯(GR)和AuNPs對于Luminol - H2O2體系的ECL具有極大的促進作用,并且殼聚糖(CS)帶正電荷,可通過靜電作用與帶負電荷的酶或者含酶的生物復(fù)合材料結(jié)合,因此該工作首先將GO、氯金酸和CS通過電化學(xué)還原沉積修飾到電極表面(dpGR-AuNPs-CS)。其次,由于Fe304具有過氧化物模擬酶的特性,可催化氧化H2O2成為各種活性氧分子,因為傳統(tǒng)的酶易失活,采用Fe304可以很好的避免酶失活的不足。另外,Ti02能增強Luminol - H2O2體系ECL信號,因此制備了帶負電荷的Fe3O4-TiO2-ChO (AMs-ChO)生物復(fù)合材料,并能成功固載到帶正電荷的電極表面,構(gòu)建了一種新型的ECL膽堿生物傳感器。該傳感器顯示出較高的靈敏度,線性范圍是0.003～1120 μmol·L-1,檢出限低至1 nmol·L-1。該傳感器具有良好的穩(wěn)定性,選擇性和很高的靈敏度,在臨床診斷方面有較好的應(yīng)用前景。
[Abstract]:Electrochemiluminescence (Electrochemiluminescence, ECL) is a certain voltage is applied on the electrode surface chemical reaction to produce some special product of electrode, between these electrodes or electrode product product and system between a component formed by electron transfer from excited state, excited state transition back to produce ground state in the process of a light radiation. It is the electrochemical method and chemiluminescence method combined with the formation of a new detection technique, which has high sensitivity, good selectivity, easy control, simple operation and other advantages. Enzyme biosensors with immobilized enzyme membrane as biological recognition element, modified electrode for signal converter, so the function of molecular recognition and selection not only has the catalytic function of the enzyme electrode, has quick response, easy operation,.ECL biosensor will be highly specific and ECL detection technology with enzyme Catalytic performance together with high sensitivity, high selectivity and so on. With the rapid development of nanotechnology, nano materials have been widely used in the field of biosensors, in the performance of nano materials of various advantages (such as a large surface area, unique electrical and chemical properties, good biocompatibility etc.). The basis for the development of biosensor has opened up a broad application prospect and high sensitive detection of the biosensor. Among them, carbon nanotubes and graphene have particular physical and chemical properties, good electrical conductivity and catalytic properties, which enables electrons between the immobilized enzyme and the electrode transfer quickly and effectively. At the same time, the construction of development based on carbon nano materials nano composite materials used in enzyme biosensor can provide good microenvironment for enzyme immobilization and maintain the enzyme from Biological activity. Based on the above considerations, this paper developed a new type of nano composite materials based on carbon nano materials and constructed a series of sensitive ECL biosensor, and the performance is compared to previous enzyme biosensor has largely improved. The main research work of this thesis are as follows: 1. multi walled carbon nanotubes composites based on the Hemin function of the electrochemiluminescence of the cholesterol biosensor work combined with multi walled carbon nanotubes (MWCNTs) on hydrogen peroxide (H202) with electro catalytic oxidation activity and Hemin on the electrochemical oxidation of H202 enhanced ECL signal characteristics of Luminol-H2O2 system, Hemin-MWCNTs new type nanocomposites were prepared and applied to detect cholesterol at first, the synthesis of Hemin-MWCNTs nano composite materials, it will drop onto the glassy carbon electrode surface treated in advance, the electrode was dried at room temperature after The surface coating of cholesterol oxidase and in 4 hours of incubation. C because Hemin-MWCNTs has good electrocatalytic properties of H2O2 enhanced ECL signal system. Under the optimum conditions, the ECL response of the sensor and the concentration of cholesterol in 3 * 10-7 to 1.2 * 10-3 mol - L-1 range show a good linear relationship, detection limit of 1 * 10-7 mol L-1.. In addition, the sensor has high sensitivity, good accuracy and stability of the advantages of.2. such as carbon nanotubes and graphene oxide based on thionine gold nanoparticles electrochemiluminescence cholesterol biosensor first, carbon nanotubes and graphene oxide (GO) in the mass ratio of 1:1 with nano composites can exhibit good electrocatalytic activity. Secondly, some reducing agent (such as toxic hydrazine), so we must control the amount. The thionine (Thionine, Thi) has a large number of hydroxyl amino and GO structure in large structure The base, can be used as some substances (e.g. chloroauric acid) of the reducing agent, reducing gold nanoparticles (AuNPs) have obtained the enormous enhancement effect for the Luminol - H2O2 system ECL, and GO as the reducing agent and reduction of chloroauric acid, can also be used as growth template AuNPs. Based on the above two points, without adding the other reducing agent, by reducing GO and Thi, MWCNTs-GO-Thi-Au nanocomposites were prepared by in situ reduction of chloroauric acid system, and the application of the nanometer composite material to detect cholesterol. Because the ECL signal of the nano composite materials of Luminol - H2O2 system has the function of amplification, the detection limit is greatly reduced under optimal conditions, the sensor showed a wide linear range (0.15 ~ 828 mol - L-1) and low detection limit (50nmol - L-1). The combination of nano composites and ECL method for detection of advantage, will this experiment. The application of biosensor in clinical biological detection has the potential value of.3. huge AMs-ChO biological composite biological functions of the ECL choline biosensor based on graphene (GR) and AuNPs for Luminol - H2O2 system ECL has great role in promoting, and chitosan (CS) with positive charge can be. Through the combination of biological composite electrostatic interaction with the negatively charged enzyme or enzyme, so the work of the GO, chloroauric acid and CS by electrochemical deposition of modified electrodes (dpGR-AuNPs-CS). Secondly, due to the nature of the Fe304 mimetic peroxidase, which can catalyze the oxidation of H2O2 into reactive oxygen molecules. Because the traditional enzyme deactivation, Fe304 can well avoid the lack of enzyme inactivation. In addition, Ti02 can enhance the Luminol - H2O2 system ECL signal, thus the preparation of the negatively charged Fe3O4-TiO2-Ch O (AMs-ChO) composite material, and can be successfully immobilized onto the electrode surface with positive charge, construction of a new type of ECL choline biosensor. The sensor showed high sensitivity, linear range is 0.003 ~ 1120 mol - L-1, the detection limit as low as 1 nmol. The sensor has a good L-1. the stability, selectivity and high sensitivity, and has a good application prospect in clinical diagnosis.

【學(xué)位授予單位】：西南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TB33;TP212.3

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本文編號：1431472