基于酶催化银沉积原理的便携式胆固醇生物传感研究

发布时间：2018-05-14 05:29

本文选题：胆固醇 + 便携式　；参考：《桂林电子科技大学》2017年硕士论文

【摘要】：胆固醇是哺乳动物体内不可或缺的重要物质,血清中的胆固醇是动脉粥样硬化斑块的主要成分。如今,人体血清中的胆固醇水平已成为临床诊断和预防心血管疾病的一个重要指标。因此,寻找高特异性和灵敏度、低成本的血清胆固醇诊断方法具有重要的临床意义。在本论文中,我们以胆固醇为检测对象,基于酶催化银沉积原理构建便携式胆固醇生物传感器。其主要研究内容如下:(1)以现场可编程门阵列(FPGA)为控制核心,以胆固醇为目标检测物,对检测信号进行放大、滤波、转换、译码并显示,构建了一种便携式的胆固醇检测系统。(2)基于双酶协同催化银沉积原理的胆固醇电化学生物传感器的构建。首先在丝网印刷电极表面沉积一层纳米金,通过静电吸附将胆固醇酯酶(CHER)和胆固醇氧化酶(CHOD)吸附到纳米金的表面,而后胆固醇在CHER和CHOD的双酶作用下水解,产生具有弱还原性的H2O2,从而将溶液中的Ag+还原成单质银并沉积在丝网印刷电极表面。使用线性扫描伏安法(LSV)检测出Ag的溶出电流,并描绘出该电流与胆固醇浓度的关系曲线。胆固醇浓度和传感器的响应信号间的关系可以表示为Y=138.9550+0.0610X(其中Y是电流响应峰值,X为胆固醇浓度),其线性范围为5~5000μg/m L,线性相关系数为0.9983,最低检测限为3.0μg/m L。该传感器特异性高,重现性好,灵敏度高。(3)基于石墨烯和酶协同催化银沉积的胆固醇电化学生物传感器的设计。首先,采用电沉积技术在丝网印刷电极表面沉积纳米金,通过静电吸附作用将滴在电极表面的石墨烯、CHER和CHOD吸附到丝网印刷电极表面,胆固醇在CHER和CHOD的作用下水解产生H2O2,H2O2和石墨烯都具有还原性,从而协同催化银沉积,将Ag+还原成Ag并沉积在丝网印刷电极表面。最后,通过线性扫描伏安法(LSV)检测出Ag的阳极溶出电流,并描绘出该电流与胆固醇浓度的关系曲线。最终得到的胆固醇浓度和传感器响应信号间的关系为Y=478.7030+0.0840X(其中Y是电流响应峰值,X为胆固醇浓度),其线性范围为0.01~5000μg/m L,其线性相关系数为0.9991,最低检测限为0.001μg/m L。
[Abstract]:Cholesterol is an essential substance in mammals, and cholesterol in serum is the main component of atherosclerotic plaques. Cholesterol levels in human serum are now an important indicator of clinical diagnosis and prevention of cardiovascular disease. The method has important clinical significance. In this paper, we set up a portable cholesterol biosensor based on the principle of enzyme catalyzed silver deposition. The main research contents are as follows: (1) using the field programmable gate array (FPGA) as the control core, the detection of cholesterol as the target, the amplification of detection signal and the filter. Wave, conversion, decoding and display, a portable cholesterol detection system is constructed. (2) the construction of a cholesterol electrochemical biosensor based on the principle of double enzyme CO catalytic silver deposition. First, a layer of nano gold is deposited on the surface of the screen printing electrode to adsorb the cholesterol esterase (CHER) and the cholesterol oxidase (CHOD) by electrostatic adsorption. On the surface of gold nanoparticles, the cholesterol was hydrolyzed under the double enzyme action of CHER and CHOD to produce a weak reductive H2O2, thus reducing the Ag+ in the solution into silver and deposited on the surface of the screen printing electrode. The linear sweep voltammetry (LSV) was used to detect the dissolution current of Ag, and the relationship between the current and the concentration of cholesterol was depicted. The relationship between the concentration of cholesterol and the response signal of the sensor can be expressed as Y=138.9550+0.0610X (in which Y is the peak of current response, X is the concentration of cholesterol), its linear range is 5~5000 g/m L, the linear correlation coefficient is 0.9983, the minimum detection limit is 3 g/m L., the sensor is highly specific, reproducible and sensitive. (3) based on graphene and The design of a cholesterol electrochemical biosensor based on the enzyme co catalyzed silver deposition was designed. First, electrodeposition was used to deposit nanoscale gold on the surface of the screen printing electrode. By electrostatic adsorption, the graphene, CHER and CHOD on the surface of the electrode were adsorbed on the surface of the screen printing electrode, and the cholesterol was hydrolyzed to produce H2O2, H2O under the action of CHER and CHOD. 2 and graphene all have reducibility, thereby co catalyzing silver deposition, reducing Ag+ into Ag and deposited on the surface of screen printing electrodes. Finally, the anode dissolution current of Ag was detected by Linear Scanning Voltammetry (LSV), and the relationship between the current and the concentration of cholesterol was depicted. The final cholesterol concentration and sensor response signal were obtained. The relationship is Y=478.7030+0.0840X (Y is the peak of current response, X is the concentration of cholesterol), and its linear range is 0.01~5000 g/m L, its linear correlation coefficient is 0.9991, and the minimum detection limit is 0.001 g/m L..

【学位授予单位】：桂林电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212.3;R446

【参考文献】