Electrochemical Microarray on Monolith Electrode: Exploratory Research

MicroRNA是一种小的20-26个核苷酸(NT)的非编码RNA，是多种疾病的有效生物标志物，包括癌症、心脏病、肥胖症和精神疾病。在过去的二十年里，很明显，对血液、尿液和组织中发现的数百个microRNA(MiRNA)分子进行分析可以在临床症状出现之前进行早期诊断。今天，没有一种廉价、可靠的方法来分析可以转化为临床环境的microRNA。微阵列是一种廉价的技术，但由于非特异性结合产生的背景信号很大，因此不可靠。该方案的目的是探索一种新的电化学方法，通过简单地扫描不同的微阵列结合位点来测量整体电极上的局部氧化还原反应来分析miRNA。电化学(氧化还原电流)信号可以潜在地区分固定的探针和目标结合之间的完美匹配，并且在非特异性结合上不发生氧化还原。当结合相对于完美结合情况具有单个失配时，用于氧化还原信号的施加电势移动。基于氧化还原电流的“主动”生物传感有可能以1阿托摩尔的灵敏度测量目标分析物分子与固定化探针的结合。通过激光扫描测量电极上局部氧化还原电流密度的电化学方法称为扫描双电层静电计(SEED)。非技术描述这项提议将开发一种新的方法来检测作为包括癌症在内的多种疾病的生物标记物的小片段核酸链。这项提议将能够使用电子测量同时检测几个不同的核酸分子。重要的是，作者将开发一种方法来检测一个电极的所有生物标记物，而不是为每个生物标记物创建单独的电极。该项目将为分析人类疾病的生物标志物提供更简单、更强大和更有信息量的方法。

Technical descriptionMicroRNA are small 20-26 nucleotide (nt) long noncoding RNA that are effective biomarkers for a variety of diseases, including cancer, heart, obesity, and mental illness. During the last two decades, it has become evident that profiling 100s of microRNA (miRNA) molecules found in blood, urine, and tissue can lead to early diagnoses before clinical symptoms appear. Today, there is no inexpensive, reliable method for profiling microRNA that can be translated to a clinic setting. Microarray is an inexpensive technology but not reliable due to large background signal from nonspecific binding. The objective of this proposal is to explore a novel electrochemical method for profiling miRNA by measuring local redox reactions on a monolith electrode by simply scanning a laser beam over various microarray binding sites. The electrochemical (redox current) signal can potentially distinguish a perfect match between an immobilized probe and a target binding, and no redox occurs on nonspecific binding. The applied electric potential for the redox signal shifts when the binding has a single mismatch relative to a perfect binding case. The "active" biosensing based on the redox current has the potential to measure binding of target analyte molecules to immobilized probes at a sensitivity of 1 atto-moles. The electrochemical method to map local redox current density over an electrode by laser scanning is called "Scanning Electrometer for Electrical Double-layer" (SEED). Non-technical descriptionThis proposal will develop a new way to sense small pieces of nucleic acid chains that serve as biomarkers of multiple diseases including cancer. The proposal will enable detection of several different nucleic acid molecules simultaneously using electrical measurements. Importantly, instead of having to create individual electrodes for each biomarker, the authors will develop a way to detect all of the biomarkers for one electrode. This project will result in simpler, more powerful and informative way of analyzing biomarkers for human diseases.