基于空心海胆状金纳米粒子和银/氧化锌纳米结构SERS特性的基因类肿瘤标志物高灵敏检测

High Sensitivity Detection of Gene-like Tumor Markers Based on SERS Characteristics of Hollow Sea-urchin Gold Nanoparticles and Noble Metal/semiconductor Substrate

基因类肿瘤标记物microRNA(miRNA)的痕量检测对于癌症早期诊断具有重要应用价值.根据空心海胆状金纳米粒子和银/氧化锌(Ag/ZnO)纳米结构的表面增强拉曼散射特性,并基于碱基互补配对原理构建探针-核酸-基底组成的"三明治"结构,提出了一种基因类肿瘤标志物miRNA的高灵敏定量检测方案.首先将捕获DNA与修饰4-巯基苯甲酸(4-MBA)的空心海胆状金纳米粒子链接作为探针,同时在Ag/ZnO纳米结构上修饰靶DNA,经与miRNA-106a互补杂交后进行SERS信号检测,获得相应的剂量-响应曲线.实验结果表明,在1 fmol·L-1至1 nmol·L-1的检测范围内,对miRNA-106a的检测限达到1.84 fmol·L-1.同时,采用实时荧光定量多聚核苷酸链式反应方法验证了基于空心海胆状金纳米粒子和Ag/ZnO纳米结构SERS特性的miRNA检测方案的可靠性.

Trace detection of genetic tumor marker microRNA(miRNA)has important application value for early diagnosis of cancer.According to the Surface-enhanced Raman Scattering characteristics of hollow sea urchin gold nanoparticles and Ag/ZnO nanostructures,and based on the principle of complementary base pairing,a"sandwich"structure of probe-nucleic acid-substrate is constructed and a highly sensitive quantitative detection scheme for genetic tumor marker miRNA is proposed.First,the captured DNA is linked to the hollow sea urchin gold nanoparticles modified with 4-mercaptobenzoic acid(4-MBA)as a probe.At the same time,the target DNA is modified on the Ag/ZnO nanostructure,and the SERS signal is detected to obtain the corresponding dose-response curve after complementary hybridization with miRNA-106 a.The experimental results show that the detection limit of miRNA-106 a reached 1.84 fmol·L-1 within the detection range of 1 fmol·L-1~1 nmol·L-1.Meanwhile,the reliability of the miRNA detection scheme based on the hollow sea urchin gold nanoparticles and Ag/ZnO nano-structure SERS characteristics was verified by the Real-time quantitative Polynucleotide Chain Reaction(RT-qPCR)method.