等离子体增强荧光及其在肝病代谢物分析中的应用研究

The level of characteristic metabolites in liver disease is one of the main assessments of liver disease. However, the detection methods of characteristic metabolites have several problems which prevent it from early diagnosis. These problems include but not limited to the insensitive analytical methods, slow analytical speed and the harsh applicable condition. This project intends to use the method of plasmon-enhanced fluorescence (PEF) to increase the sensitivity, takes the advantage of hydrophilic polymer brush to improve the analytical condition, thus they could be used in the detection of metabolites in complex analysis system. Then combined with studying the mechanism of fluorescent enhancement, different fluorescent materials will be used in PEF. In order to obtain a selective fluorescence probe, the method of grafting will be optimized. At the same time, the molecular weight of the polymer brush is also optimized for anti-protein adsorption. Based on the above studies, we want to establish a sensitive, fast and accurate method to detect the bile acid or lipopolysaccharide. The relationship between the liver diseases and their characteristic metabolites will be also established. At the same time, the early diagnosis of liver disease will be supported with theory and research data.

肝病特征代谢物水平是目前肝病诊断的依据之一，而目前采用的肝病特征代谢物检测存在检测灵敏度不高、样品前处理繁杂、样品检测条件苛刻等问题，限制了肝病的早期诊断。本项目拟通过等离子增强荧光的方法提高肝病代谢物检测的灵敏度，采用亲水性高分子刷接枝的方式提高荧光探针抵抗蛋白的能力，采用靶标物接枝的方式，提高荧光探针的特异性。研究中将深入探索壳层隔绝纳米粒子增强荧光的调节规律和增强机理，实现不同荧光材料的荧光增强；优化靶标物接枝方式及高分子刷分子量大小，实现荧光探针在复杂基质中高选择性荧光定量检测。并由此发展一种适用于复杂体系的灵敏、快速、选择性检测肝病代谢物的方法，建立和完善肝病与其代谢物之间的联系，为肝病的早期诊断和治疗提供理论和数据支持。

针对肝病代谢物检测方法灵敏度低、前处理复杂等问题，本课题通过等离子增强量子点或荧光染料的荧光强度，提高荧光检测的灵敏度；以亲水性刷修饰的方式，提高了荧光探针在检测基质中抵抗蛋白的能力。研究中以肝病代谢物脂多糖和胆汁酸为研究对象，主要开展了以下四方面的工作：（一）以金纳米粒子为激元，以量子点为等离子增强荧光物质，以多肽为特异性识别元件，用于等离子增强荧光高灵敏检测脂多糖；（二）以银纳米粒子为等离子增强激元，以量子点为荧光物质，以适配体为识别元件，用于等离子增强荧光检测胆汁酸；（三）采用亲水性高分子刷接枝的方式，一方面控制等离子激元金纳米棒与近红外荧光染料之间的距离，一方面提高荧光探针在检测基质中抵抗蛋白的能力，用于脂多糖的可视化快速检测；（四）采用智能手机与适配体修饰比率荧光探针相结合的方式发展了脂多糖可视化检测方法。通过红外光谱、透射电镜、Zeta电位表征了探针的结构；通过荧光光谱、紫外可见吸收光谱、3D-FDTD模拟探究了等离子增强荧光的机理；通过多肽、适配体等不同靶标物修饰提高探针检测的特异性；通过实际样品检测验证了方法的准确性；通过与传统检测方法的线性范围、检出限以及检测时间等进行对比验证，突出了探针的灵敏度和便携性，从而建立了肝病代谢物检测方法，为临床医学、环境检测提供了可选择的方法。