金银纳米颗粒应用于氨基酸的可视化检测

发布时间：2018-04-10 09:24

本文选题：金银纳米　切入点：比色法　出处：《南昌大学》2017年硕士论文

【摘要】：贵金属纳米材料因为具有独特的金属物理化学性质以及优异的光学性能而被广泛关注并且应用于化学催化、医用材料、传感材料等领域。尤其针对于金银纳米材料,由于其光电学性质小尺寸效应、良好的稳定性以及特异的生物亲和性,显示其具有很高的潜在价值,成为了热点研究领域。本文设计了四种不同方法的金银纳米材料用于氨基酸的特异性识别,分别建立了蛋氨酸、谷胱甘肽、组氨酸的定量分析方法,研究结果包括以下几个方面:(1)基于蛋氨酸抑制三聚氰胺诱导的金纳米聚集而建立的可视化蛋氨酸的检测。在优化实验条件下,采用柠檬酸钠作为还原剂和稳定剂合成粒径为13.0nm左右、分散性良好的AuNPs溶胶。三聚氰胺结构中含有三个氨基,与金属有较强的配位作用,因此它们通过与金纳米表面的柠檬酸根负离子进行配位体交换作用而导致金纳米由分散状态变为高度聚集状态,纳米金溶胶的颜色由酒红色逐渐变为紫色最终变为蓝色。由于蛋氨酸与金纳米通过N-Au与S-Au键的共同作用而结合,所以随着蛋氨酸溶液的加入,逐渐抑制了三聚氰胺诱导的金纳米溶胶的聚集,溶液由蓝色逐渐变为酒红色,从而实现对目标氨基酸蛋氨酸快速、简便、灵敏的定量检测。上述传感机理通过透射电镜以及纳米粒径分析仪得以验证。试验结果显示,蛋氨酸浓度的裸眼最低检出量为0.4μM,采用紫外光谱进行定量分析可得到其在0.1-1.0μM范围内的理论检测限(LOD)为24.5nM,本方法成功应用到了尿样及血清中蛋氨酸的检测,平均回收率在95%-105%之间。(2)根据抑制金纳米聚集设计了一种快速、灵敏的谷胱甘肽检测方法。2.0μM的2-巯基-1-甲基咪唑作为聚集剂能够使金纳米发生明显的聚集,同时伴随着颜色由红色变为紫色再到蓝色。Cys在pH为5.8±0.1时能使AuNPs聚集,颜色发生明显改变,由酒红色变为紫色,对于Hcy而言,当pH大于11时,会引起AuNPs的聚集,但是当pH在5-7之间时,则会使AuNPs处于分散状态,对于GSH而言,当其与AuNPs混合时,在pH小于4.5时与AuNPs颗粒结合的GSH的两个羧基间发生氢键作用,使AuNPs发生聚集,当pH大于4.5时,由于羧基的去质子化作用,AuNPs则不会发生聚集。由此可知,改变溶液的pH可有效改善本方法的选择性,将溶液的pH调节为5.8时,Cys/AuNPs和Hcy/AuNPs会发生聚集,而GSH/AuNPs仍处于分散状态。金纳米的聚集程度随着谷胱甘肽浓度的提高而逐渐降低,金纳米由蓝色逐渐变为酒红色,肉眼可观察到的最低谷胱甘肽检测量为0.1μM,利用紫外光谱进行低浓度定量分析,谷胱甘肽浓度在0.1-1.0μM范围内的理论检测限为12.0 nM。该方法成功的应用于人体血样和尿样中谷胱甘肽的检测,平均回收率在95%-103%之间。(3)基于谷胱甘肽抑制半胱氨酸诱导金纳米聚集而建立的可视化谷胱甘肽的检测。由上一个检测谷胱甘肽的实验原理可知,在pH为5.8的条件下,胱氨酸,高半胱氨酸等含巯基化合物不能使其聚集亦或有较轻微的聚集,而半胱氨酸能够使金纳米发生聚集,并且随着半胱氨酸浓度的增加,金纳米颜色由酒红色变为紫色。pH的大小能够决定AuNPs是否聚集以及聚集程度,因此选用半胱氨酸作为聚集剂,有趣的是,谷胱甘肽和半胱氨酸经常由于结构类似而难以区分,而在此体系中,设计的实验本身就能够将两者区分开来。当加入谷胱甘肽后,随着谷胱甘肽的不断加入,溶液颜色逐渐由紫色变为酒红色,从而实现对谷胱甘肽的定量检测分析。该方法成功地应用于人体血样和尿样中谷胱甘肽的检测,平均回收率在90%-110%之间。(4)利用对氨基苯磺酸修饰的银纳米(AgNPs)对组氨酸(His)进行了比色检测。在优化实验条件下,采用硼氢化钠还原法合成粒径为6.7 nm左右、分散性良好的SAA-AgNPs探针。通过透射电镜、红外光谱以及紫外光谱对其结构进行了表征,本实验利用组氨酸诱导SAA-AgNPs溶胶的聚集,从而达到定量检测组氨酸的目的。首先,我们发现His有咪唑环,而SAA有芳香环,我们推测咪唑环和芳香环之间的π-π键堆积作用会使SAA-AgNPs发生一定程度的聚集,其次,SAA上的氨基与His的羧基之间的静电作用对于SAA-AgNPs的聚集也是必不可少的,最后,对氨基苯磺酸作为识别功能团与组氨酸通过氢键作用同样对银纳米发生聚集起到了一定的作用。根据以上机理,随着组氨酸浓度的增加,银纳米颜色由亮黄色变为橘色再到紫色,通过颜色变化和紫外吸收光谱变化分别实现了组氨酸的定性和定量分析,在0-3.5μM范围内其的检测限为52.7nM,能够成功的运用于实际血清样品的检测,血清样品回收率为97%-107%之间。
[Abstract]:Noble metal nano materials because of its unique physical and chemical properties of the metal and excellent optical properties and have been widely concerned and applied in chemical catalysis, medical materials, field sensing materials. Especially for gold and silver nano material, because of its optical and electrical properties? Small size effect, good stability and specific biological affinity, display it has high potential value, has become a hot research field. This paper designed the silver nano materials of four different methods for identification of specific amino acid, methionine and glutathione were established, the quantitative analysis method of histidine, the results of the study include the following aspects: (1) the establishment of methionine and methionine visualdetection inhibition of melamine based on the aggregation of gold nanoparticles induced. Under the optimized experimental conditions, using sodium citrate as reducing agent and stabilizer as the particle size of 13.0nm So, good dispersion of AuNPs sol. Melamine structure containing three amino groups, strong complexation with metal, so they through the ligand exchange interaction caused by the dispersion of gold nanoparticles into high aggregation and citrate anion gold nanoparticles, gold nanoparticles by the color of wine red gradually become purple and eventually become blue. Because of methionine and gold nanoparticles by both the N-Au and S-Au key combination, so with the addition of methionine solution, gradually inhibited the nano gold sol melamine induced aggregation solution gradually changed from blue to red wine, in order to achieve the target amino acid methionine fast, simple. The quantitative detection sensitivity. The sensing mechanism by TEM and nano particle size analyzer has been verified. The test results show that the uncorrected minimum detectable amount of methionine concentration was 0 .4 M, the quantitative analysis can be obtained in the 0.1-1.0 M within the scope of the theory of limit of detection by UV spectrum of (LOD) 24.5nM, this method was successfully applied to the detection of methionine in serum and urine, the average recovery rate was 95%-105%. (2) according to the inhibition of gold nanoparticles and design a aggregation rapid and sensitive methods for detection of glutathione.2.0 M 2- mercapto -1- methyl imidazole as aggregation agent can make obvious aggregation of gold nanoparticles, accompanied by the color changes from red to purple to blue.Cys in pH was 5.8 + 0.1 to AuNPs aggregation, color change from red to purple wine and for Hcy, when the pH is greater than 11, will cause the aggregation of AuNPs, but when the pH is in between the 5-7, will make AuNPs in a decentralized state, for GSH, when mixed with AuNPs, there are two carboxyl groups in pH is less than 4.5 and AuNPs particles with the GSH between Hydrogen bonding, AuNPs aggregation, when more than 4.5 pH, carboxyl groups due to deprotonation, AuNPs will not occur together. Therefore, changing the pH of the solution can effectively improve the selectivity of the method, the pH of the solution is adjusted to 5.8, Cys/AuNPs and Hcy/AuNPs will be aggregated, while GSH/AuNPs was still in a decentralized state the degree of aggregation. The gold nanoparticles decreased with the increase of the concentration of glutathione, gold nanoparticles gradually changed from blue to red wine, the minimum amount of glutathione detection visible for 0.1 M, quantitative analysis of low concentration by UV spectroscopy, glutathione concentration in the 0.1-1.0 M within the scope of the theoretical detection limit of detection 12 the nM. method has been successfully applied to human glutathione in blood and urine, the average recovery rate was 95%-103%. (3) glutathione induced inhibition of cysteine gold nanoparticles aggregation is established based on the Visual detection of glutathione. By the experimental detection of glutathione on a principle that, in the case of pH is 5.8, cystine, cysteine containing sulfhydryl compounds which could not be gathered or gathered and slight, cysteine can make the aggregation of gold nanoparticles, and with the increase of the concentration of cysteine. The nano gold color from red to purple wine with the size of.PH to determine whether the AuNPs aggregation and aggregation degree, therefore the selection of cysteine as aggregation agent, interestingly, glutathione and cysteine often due to similar structure but difficult to distinguish, and in this system, the design of the experiment itself can distinguish the two. When adding glutathione and with the continuous addition of glutathione, the color of the solution gradually from purple to red wine, so as to realize the quantitative detection and analysis of glutathione. The application of this method successfully In the detection of human glutathione in blood and urine, the average recovery rate was 90%-110%. (4) using modified sulfanilic acid nano silver (AgNPs) of histidine (His) by colorimetric detection. Under the optimized experimental conditions, using sodium borohydride reduction method for the synthesis of a size of about 6.7 nm dispersion SAA-AgNPs probe good. By TEM, the structure was characterized by infrared spectroscopy and UV spectroscopy, this experiment using histidine SAA-AgNPs sol induced aggregation, so as to achieve the purpose of quantitative detection of histidine. First of all, we found that His and SAA have imidazole ring, aromatic ring, we speculate that the imidazole ring and aromatic ring the PI pi bond accumulation will make SAA-AgNPs in a certain degree of aggregation, secondly, the electrostatic interaction between amino and carboxyl group on the His SAA is essential for the aggregation of SAA-AgNPs,, p-Aminobenzene Sulfonic The acid functional group and histidine as recognition by hydrogen bonding to silver nanoparticles occurred to some extent gathered. According to the above mechanism, with the increase of the concentration of histidine, nano silver color changed from light yellow to orange to purple, the color changes and UV absorption were achieved by qualitative and quantitative analysis of the optical spectra of histidine changes in 0-3.5 M within the scope of the detection limit is 52.7nM, the detection can be successfully applied to the actual samples of serum, serum sample recovery rate was 97%-107%.

【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;O657.3

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