基于石墨烯—金纳米颗粒复合材料的SPR传感器研究

发布时间：2018-07-10 07:13

本文选题：石墨烯-金纳米颗粒复合材料 + 表面等离子体共振　；参考：《湖南大学》2016年硕士论文

【摘要】：石墨烯-金纳米颗粒复合材料具有优越的催化活性、增强的电子转移能力和显著增大的比表面积等优点,因此已被广泛用于电化学生物传感器和光学生物传感器的构建。结合石墨烯-金纳米颗粒复合材料构建SPR传感器,可以提高传感器的灵敏度,扩大其应用范围。目前已有文献报道利用基于氧化石墨烯-金纳米颗粒(GO-AuNPs)复合材料的SPR传感器检测小分子或蛋白质,在这些工作中,GO-AuNPs复合材料仅作为基底以固定识别分子,鲜少有文献报道利用GO-AuNPs复合材料做信号分子放大SPR信号。鉴于miRNA是一种重要的癌症生物标记物,发展高灵敏检测miRNA的方法对于癌症的诊断和治疗是非常有意义的,本文以miRNA-141为检测对象,结合GO-AuNPs复合材料的优越性能,构建了以下SPR传感器,具体如下：1.基于GO-AuNPs复合材料信号分子的SPR传感器用于miRNA的检测研究。该传感器只需要简单的两步就可以实现对miRNA的检测,第一步：利用金膜表面修饰的捕获探针DNA识别固定目标miRNA-141;第二步：GO-AuNPs复合材料表面修饰的辅助DNA与目标miRNA杂交,最终形成捕获探针DNA/目标miRNA/GO-AuNPs复合材料的三明治结构。该传感器的检测限能达到1 fM,而且具有良好的选择性,能够识别miRNA-200家族成员间的不同。同时利用该传感器检测细胞提取物总RNA中miRNA-141的含量,并与qRT-PCR法进行比较,两者结果一致,说明该传感器能用于复杂样品的检测。2.基于GO-AuNPs复合材料的SPR传感器用于miRNA和腺苷的检测研究。在前面工作的基础上,将GO-AuNPs复合材料修饰在金膜上,将其作为增强的传感基底以固定捕获探针DNA,并以辅助DNA修饰的GO-AuNPs复合材料作为信号分子,两者结合构建SPR传感器,通过传感芯片与信号分子的双重信号放大实现对miRNA的高灵敏检测。该传感器可检测低至O.1 fM的miRNA-141,具有较好的选择性,并可用于检测癌细胞提取物总RNA中的miRNA-141。同时,基于腺苷与其裂开式核酸适配体之间的特异性结合,该传感也可实现对腺苷的检测,其检测限为0.1 pM,说明该传感器具有较好的通用性。
[Abstract]:Graphene-gold nanoparticles composites have been widely used in electrochemical biosensors and optical biosensors because of their excellent catalytic activity, enhanced electron transfer ability and significantly increased specific surface area. The SPR sensor based on graphene-gold nanoparticles composite can improve the sensitivity of the sensor and expand its application range. It has been reported that the SPR sensor based on graphene oxide / gold nanoparticles (GO-AuNPs) composite is used to detect small molecules or proteins. Few literatures have reported using GO-AuNPs as signal molecules to amplify SPR signals. Since miRNA is an important biomarker for cancer, the development of highly sensitive methods for the detection of miRNA is of great significance for the diagnosis and treatment of cancer. In this paper, miRNA-141 is used as a detection object and the superior properties of GO-AuNPs composite are combined. The following SPR sensors are constructed, as follows: 1. The SPR sensor based on GO-AuNPs composite signal molecule is used to detect miRNA. The sensor requires only two simple steps to detect miRNA. The first step is to identify the fixed target miRNA-141 by using the captured probe DNA modified by the gold film surface, and the second step is to hybridize the auxiliary DNA modified with the target miRNA by the surface modification of the GO-AuNPs composite. Finally, the sandwich structure of capture probe DNA / target miRNA / GO-AuNPs composite was formed. The detection limit of the sensor can reach 1 fM, and it has good selectivity, and it can recognize the difference between the members of miRNA-200 family. At the same time, the content of miRNA-141 in total RNA of cell extract was detected by the sensor, and compared with qRT-PCR. The results were consistent, which indicated that the sensor could be used for the detection of complex samples. SPR sensors based on GO-AuNPs composites were used to detect miRNA and adenosine. On the basis of the previous work, the GO-AuNPs composite was modified on the gold film, which was used as an enhanced sensing substrate to immobilize the probe DNA, and the GO-AuNPs composite modified with the auxiliary DNA was used as the signal molecule. The SPR sensor was constructed by combining the GO-AuNPs composite with the GO-AuNPs composite as the signal molecule. The high sensitivity detection of miRNA is realized by double signal amplification of sensor chip and signal molecule. The sensor can be used to detect miRNA-141 as low as O.1 FM, and can be used to detect miRNA-141 in total RNA of cancer cell extract. At the same time, based on the specific binding between adenosine and its split-type aptamer, the sensor can also detect adenosine with a detection limit of 0.1 pm, which indicates that the sensor has good versatility.
【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB33;TP212

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