电化学方法在吗啡检测中的应用

发布时间：2018-12-21 08:56

【摘要】： 近年来，随着国际毒品走私活动的猖獗，国内的毒品犯罪也呈现上升趋势，越来越多的人开始吸食毒品，而其中大部分是青少年。毒品犯罪已经成为青少年犯罪的一个重要方面，如何实现对毒品的快速分析认定，对戒毒过程的监测以及打击毒品走私和开展禁毒工作都十分重要。传统的检测手段多是利用气相色谱、液相色谱、质谱或者是几种检测手段的联用，这些传统的检测手段虽然灵敏度和准确性都比较高，但是这种检测方法都需要大型的仪器而且必须是专业人员操作，已不能适应现代社会禁毒工作的需要。电化学分析作为一种独立的分析检测手段，近期被广泛应用于毒品的分析鉴定，尤其是生物传感器的开发，为电化学手段分析毒品的代谢产物拓宽了道路。本论文以导电玻璃(ITO)为基体电极，选用盐酸吗啡为检测对象，以不同的修饰手段来探讨电化学分析方法在毒品检测中的应用，建立了一套较完整的应用于电分析化学的表征体系，并探讨了几种不同电极制备方法的优势以及其发展前景。论文首先研究了以普鲁士蓝(PB)修饰的导电玻璃(ITO)对吗啡的电化学响应。发现修饰后的电极对吗啡的电化学响应与空白ITO相比明显增大。通过扫描电镜(SEM)表征，我们发现PB修饰后的电极表面活性面积明显增大，为了解决PB修饰电极的易毒化问题，我们尝试了先在ITO上面镀一层IrO_2然后在对其进行修饰等方法，可惜并没有取得预期的效果。其次，在进行第一步试验尝试后我们发现，只用IrO_2修饰的ITO电极，对吗啡有较好的电化学响应。围绕此种电极，我们建立了以电化学响应电位、响应峰电流密度、线性响应区间等为基准的一套表征方案。在本论文中，我们以IrO_2修饰的ITO电极为工作电极，，循环伏安法为主要测试手段，得出了该种电极对吗啡的响应电位为0．79V(vs．Ag/AgCl)，线性响应区间为5×10~(-7)-5×10~(-3)mol·dm~(-3)，在吗啡浓度为5×10~(-4)mol·dm~(-3)时其峰电流密度为7×10~(-5)A/cm~2。此外，初步探讨了高温处理对电极的吗啡响应性能的影响，发现其响应随处理温度的升高而降低。最后，我们尝试利用导电聚合物修饰电极来检测吗啡。以ITO为基体，采用水相阳极电沉积了3，4-乙撑二氧噻吩(EDOT)修饰电极，并研究了沉积电量和沉积电位对电极的吗啡响应活性的影响。发现沉积电位为1．2V(vs．Ag／AgCl电极)，沉积电量为20-40mC(电极面积为1×0．8cm~2)时所得的聚合物修饰电极对吗啡的电化学响应最大。在此基础上，研究了聚EDOT膜修饰电极在不同浓度的吗啡水溶液中的电化学检测，发现在0．05-6 mmol·dm~(-3)浓度范围内具有很好的线性响应，最低检测限为0．05mmol·dm~(-3)，相关系数达0．995。
[Abstract]:In recent years, with the rampant international drug smuggling activities, domestic drug crimes also show an upward trend, more and more people began to take drugs, and most of them are teenagers. Drug crime has become an important aspect of juvenile delinquency. It is very important to monitor the process of detoxification, crack down on drug smuggling and carry out anti-drug work. Most of the traditional methods of detection are gas chromatography, liquid chromatography, mass spectrometry or the combination of several detection methods. Although the sensitivity and accuracy of these traditional detection methods are relatively high, However, all of these methods need large scale instruments and must be operated by professionals, which can not meet the needs of drug control in modern society. Electrochemical analysis as an independent means of analysis and detection has recently been widely used in drug analysis and identification, especially the development of biosensor, which opens the way for electrochemical analysis of drug metabolites. Using conductive glass (ITO) as substrate electrode and morphine hydrochloride as detection object, the application of electrochemical analysis method in drug detection was studied by different modification methods. A complete characterization system for electroanalytical chemistry was established, and the advantages and prospects of several different electrode preparation methods were discussed. The electrochemical response of conductive glass (ITO) modified with Prussian blue (PB) to morphine was studied. It was found that the electrochemical response of the modified electrode to morphine was significantly higher than that of blank ITO. By scanning electron microscopy (SEM) characterization, we found that the surface active area of the electrode modified by PB was obviously increased, in order to solve the problem of easy toxicity of PB modified electrode. We tried to coat the ITO with a layer of IrO_2 and then decorated it, but the desired results were not achieved. Secondly, after the first step experiment, we found that the IrO_2 modified ITO electrode had a good electrochemical response to morphine. Based on the electrochemical response potential, the response peak current density and the linear response range, a set of characterization schemes have been developed. In this thesis, the IrO_2 modified ITO electrode was used as the working electrode and the cyclic voltammetry was used as the main test method. The response potential of the electrode to morphine was 0.79 V (vs.Ag/AgCl). The linear response range is 5 脳 10 ~ (-7) -5 脳 10 ~ (-3) mol dm~ (-3), and the peak current density is 7 脳 10 ~ (-5) A / cm ~ (-3) when morphine concentration is 5 脳 10 ~ (-4) mol dm~ (-3). In addition, the effect of high temperature treatment on the morphine response of the electrode was preliminarily discussed, and it was found that the response decreased with the increase of the treatment temperature. Finally, we try to use conductive polymer modified electrode to detect morphine. Using ITO as the substrate, the (EDOT) modified electrode was electrodeposited by anodic electrodeposition of 3o 4- ethylenedioxythiophene, and the effects of deposition energy and deposition potential on the morphine-responsive activity of the electrode were studied. When the deposition potential is 1.2 V (vs.Ag/AgCl electrode) and the deposition charge is 20-40mC (electrode area is 1 脳 0.8cm~2), the electrochemical response of the polymer modified electrode to morphine is the greatest. On this basis, the electrochemical detection of poly (EDOT) membrane modified electrode in different concentrations of morphine aqueous solution was studied. It was found that there was a good linear response in the concentration range of 0.05-6 mmol dm~ (-3). The lowest detection limit was 0.05mmol dm~ (-3), and the correlation coefficient was 0.995.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2008
【分类号】：D918.2

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