µROX - µRNA Redox cycling

该项目旨在开发一种快速、低成本和超灵敏的电化学芯片实验室(LOC)平台，该平台包含多路微流控技术，无需任何样品处理即可同时检测不同的microRNA(微RNA)。微RNA是一种非编码的小RNA分子，作为诊断和预后的生物标志物具有潜在的作用。如今，在集中式实验室中有许多不同的诊断平台来进行µRNA分析。然而，由于它们的设备笨重和昂贵，以及需要进行样品处理以及高样本量，它们不适合应用于护理点检测(POCT)。为了满足对便携式和快速护理点设备的需求，实现LOC平台非常重要，该平台允许以快速的样品到结果时间(例如，无需任何样品制备)以及低样品消耗(例如，手指扎出的血液)来测量多个微RNA。微流控LOC平台加速了对各种生物标志物的特异和灵敏的检测。提出的电化学微核糖核酸传感器是基于不同放大技术的组合。为了提高器件的灵敏度，采用了间隙尺寸在纳米范围内的交指电极阵列。在这方面，将调查技术限制，以实现可能的最高放大。为了获得酶介导的信号放大，采用了停流技术。进一步的信号放大是通过DNA或RNA菌株和/或通过适当的表面修饰来增加结合位点数来实现的。与传统的电化学方法相比，这些扩增方法的结合大大提高了灵敏度，无需事先通过聚合酶链式反应(PCR)技术进行扩增，即可快速、可靠地测量微RNA。微RNA的一个具体应用是幼儿侵袭性脑瘤(最早发病18个月)，称为髓母细胞瘤(MB)，样本量很少。除组织病理学分类外，MB还可分为四种分子亚型。早期对这些亚型进行分类或检测复发将增加患者的生存机会。这项提议致力于利用不同研究领域(微纳米技术、微流体和生物医学)的独特相互作用，为癌症研究实施一种新的检测方法。多路复用µRNA图谱系统的成功演示将对临床诊断产生重大影响，特别是在POCT中，并将成为标准PCR系统和其他诊断系统的低成本和用户友好型替代方案。此外，不仅可以在血浆、唾液和尿液等样本中测量微RNA，还可以直接在未稀释的血清甚至全血中测量微RNA。

This project aims to develop a rapid, low-cost and ultrasensitive electrochemical lab-on-a-chip (LOC) platform comprising multiplexed microfluidics for the simultaneous detection of different microRNAs (µRNAs) without any sample treatment. µRNAs, small non-coding RNA molecules, play a potential role as diagnostic and prognostic biomarkers. Nowadays there are many different diagnostic platforms for the µRNA profiling in centralized laboratories. However, due to their bulky and expensive equipment, and their need for a sample treatment along with a high sample volume they are not suitable for an application in point-of-care testing (POCT). To cover the demand for portable and fast point-of-care devices it is of great importance to realize a LOC platform allowing the measurement of multiple µRNAs with fast sample-to-result times (e.g. without any sample preparation) along with a low sample consumption (e.g. blood from a finger prick). Microfluidic LOC platforms offer an acceleration of the specific and sensitive detection of various biomarkers. The proposed electrochemical µRNA sensor is based on the combination of different amplification techniques. To increase the device sensitivity, interdigitated electrode arrays with gap sizes in the nanometer range are employed. In this regard, the technological limits will be investigated to achieve the possible highest amplification. In order to obtain enzyme-mediated signal amplification, the stop-flow technique is utilized. A further signal amplification is achieved by DNA or RNA strains and/or by an appropriate surface modification to increase the number of binding sites. The combination of these amplification approaches represents a drastic increase in sensitivity compared to the conventional electrochemical methods and allows a fast and reliable measurement of µRNAs without prior amplification by means of polymerase chain reaction (PCR) techniques. One of the specific applications for µRNAs, where only a low sample volume is available, is the aggressive brain tumor in young children (earliest incidence 18 month), known as Medulloblastoma (MB). Beside the histopathologic classification of MB, it can be divided into four molecular subtypes. An early classification of these subtypes or detection of relapse will increase the survival chances of patients. This proposal is dedicated to implement a new detection method for cancer research using a unique interplay of different research fields (Micro-Nanotechnology, microfluidics and biomedicine). A successful demonstration of the multiplexed µRNA profiling system will have a great impact on clinical diagnostics, especially in POCT, and will be a low-cost and user-friendly alternative to standard PCR systems and other diagnostics systems. Furthermore, it will be possible to measure µRNAs not only in samples like blood plasma, saliva and urine, but also directly in undiluted serum or even whole blood.