纳米金比色法检测克伦特罗和凝血酶

【作者】 李静；

【导师】 李保新；

【作者基本信息】 陕西师范大学 ， 分析化学， 2012， 硕士

【摘要】 纳米金比色法具有简单、快速、成本低廉等优点,引起研究者广泛关注。本论文以纳米金粒子作为比色探针,建立了检测克伦特罗和凝血酶的新分析方法。一、以表面带负电荷纳米金粒子为比色探针检测克伦特罗克伦特罗俗称“瘦肉精”,能使动物体内的脂肪转化为蛋白质。为了增加动物的瘦肉量,克伦特罗被非法地添加到饲料中。然而,食用含克伦特罗残留的肉制品会导致中毒。因此建立简单、快速、灵敏测定克伦特罗的分析方法具有重要的意义。本文发现克伦特罗可以使纳米金粒子发生团聚,从而使纳米金溶液的颜色从红色变为蓝色。据此现象,建立了一种测定克伦特罗的新方法。在优化的实验条件下,克伦特罗的浓度在2.0×10-9-1.0×10-6M范围内与纳米金溶液的吸光度比值(A640/A520)呈良好的线性关系,方法检出限为0.61nM。本法无需大型仪器,具有简单、快速、灵敏度高等优点,已应用于猪尿液中克伦特罗的检测,结果令人满意。二、基于表面带正电荷纳米金粒子与凝血酶适配体的相互作用比色法测定凝血酶凝血酶是一种丝氨酸蛋白酶,在心血管疾病的形成以及血液凝固、炎症和创伤愈合等生理和病理过程中起到重要作用。我们制备了表面带正电荷的纳米金粒子。实验发现单链DNA(一种聚阴离子)可以通过静电作用引起正电荷纳米金粒子团聚。本文以凝血酶适配体作为模型体系,将纳米金比色法与适配体的分子识别相结合构建测定凝血酶的新方法。实验结果表明游离的凝血酶适配体可以使纳米金粒子团聚,而凝血酶适配体与凝血酶结合后不能使纳米金粒子团聚,且纳米金粒子的团聚程度与凝血酶浓度密切相关。在优化的实验条件下,凝血酶浓度在0.5-400nM范围内与纳米金溶液的吸光度比值(A650/A524)呈良好的线性关系。且裸眼可检测浓度为50nM的凝血酶。本法无需标记、简单、快速,在生物传感中具有很好的应用前景。更多还原

【Abstract】 The gold nanoparticles (AuNPs) colorimetric method has aroused attention because of its many advantages, such as special spectral properties, rapidly, simplicity, and no large-scale instrument. In this paper, we explored the AuNPs-based colorimetric assays for clenbuterol and thrombin.1. Simple and sensitive detection of clenbuterol using gold nanoparticles as colorimetric probesA simple and sensitive method for the detection of clenbuterol was described using AuNPs as the colorimetric probes. Clenbuterol could induce the aggregation of AuNPs, resulting in a color change from red to blue or purple. The concentration of clenbuterol could be determined with the naked eye or the UV-vis spectrometer. Results showed that a linear response toward clenbuterol concentration in the range from2.0×10-9M to1.0×10-6M with the detection limit of0.61nM. This method had such advantages as sensitive, simple, inexpensive and wide linear range, which provided a potentially useful tool for the clenbuterol detection. The mechanism of the aggregation of the AuNPs in this system was discussed.2. Simple and sensitive aptamer-based sensing of thrombin with positive-charged gold nanoparticle as colorimetric probesIn this work, a simple and sensitive aptamer-based colorimetric method for thrombin detection using positive-charged gold nanoparticle probes has been reported. In the absence of thrombin, the negatively-charged thrombin aptamer (TBA) has strong binding ability to the surface of positively-charged AuNPs through electrostatic interaction, which leads to their aggregation and a consequent an obvious color change of positively-charged AuNPs from wine red to blue. In the prescence of thrombin, thrombin would interact with TBA and induce TBA to fold into a G-quadruplex structure, and the G-quadruplex could not induce the aggration of AuNPs. This color change was dependent on the concentration of thrombin, realizing the detection of thrombin in a very convenient way. A linear range from0.5to400nM is obtained for thrombin, which is as low as the most sensitive methods. Significant color change is visible at as low as50nM. This method has such advantages as sensitive, simple, and inexpensive, which provides a potentially useful tool for the thrombin detection.更多还原