Electron Transfer Mediated Electrochemical Biosensor for MicroRNAs Detection Based on Metal Ion Functionalized Titanium Phosphate Nanospheres at Attomole Level
Electron Transfer Mediated Electrochemical Biosensor for MicroRNAs Detection Based on Metal Ion Functionalized Titanium Phosphate Nanospheres at Attomole Level
复制标题
基于金属离子功能化磷酸钛纳米球的阿托摩尔级电子转移介导的MicroRNA检测电化学生物传感器
DOI：
10.1021/am508690x
复制
发表时间：
2015-02-04
影响因子：
9.5
通讯作者：
Zhu, Jun-Jie
中科院分区：
文献类型：
--
作者：
Cheng, Fang-Fang;He, Ting-Ting;Zhu, Jun-Jie
MicroRNAs （miRNAs）已成为多种癌症诊断和预后生物标志物的新候选；因此，灵敏和选择性地检测microrna对早期癌症诊断和疾病预防具有重要意义。以Cd2+修饰的磷酸钛纳米颗粒为信号单元，两个DNA作为捕获探针，Ru(NH3)(63)（+）作为电子传递介质，研制了一种新型、简单的电化学miRNA生物传感器。在磷酸钛球中加入大量镉离子，输出电化学信号。由于Ru(NH3)(63)（+）分子作为电子线与DNA碱基对相互作用，电化学信号显著提高了5倍以上。该方法实现了从1.0 aM到10.0 pM的宽动态线性范围，超低限检测为0.76 aM，大大提高了灵敏度。此外，所提出的生物传感器具有足够的选择性，可以从同源mirna中区分目标mirna，并可用于快速和直接分析人血清中的mirna。因此，该策略为生物医学研究和临床诊断中的miRNA表达谱分析提供了一个新的超灵敏平台。
MicroRNAs (miRNAs) have emerged as new candidates as diagnostic and prognostic biomarkers for the detection of a wide variety of cancers; thus, sensitive and selective detection of microRNAs is significant for early-phase cancer diagnosis and disease prevention. A novel and simple electrochemical miRNA biosensor was developed using Cd2+-modified titanium phosphate nanoparticles as signal unit, two DNA as capture probes, and Ru(NH3)(63)(+) as electron transfer mediator. Large quantities of cadmium ions were mounted in titanium phosphate spheres to output the electrochemical signal. Because of the presence of Ru(NH3)(63)(+) molecules that interacted with DNA base-pairs as electron wire, the electrochemical signal significantly increased more than 5 times. This approach achieved a wide dynamic linear range from 1.0 aM to 10.0 pM with an ultralow limit detection of 0.76 aM, exerting a substantial enhancement in sensitivity. Moreover, the proposed biosensor was sufficiently selective to discriminate the target miRNAs from homologous miRNAs and could be used for rapid and direct analysis of miRNAs in human serum. Therefore, this strategy provides a new and ultrasensitive platform for miRNA expression profiling in biomedical research and clinical diagnosis.