Small RNAs have been considered as potential biomarkers of various human diseases. Sensitive and multiplexed determination of small RNAs with point-of-care (POC) assay would be of great significance. Herein, an integrated paperfluidic chip device for multiplexed small RNA analysis was developed for the first time. In this system, the extraction and purification of small RNA was completed through a poly(ether sulfone) (PES) paper chip without the need for centrifugation. Subsequently, a newly designed hairpin probe–exponential amplification reaction (HP–EXPAR) was directly performed within the extraction paper chip. For the simultaneous realization of multiple detection, a multilayer paper chip was designed in a foldable manner with more portability and usability. Quantum dots (QDs) were employed as signal labels, which endowed this assay with high optical detection efficiency. Moreover, magnetic sheets were introduced as an alternative method for layer stacking, not only guaranteeing adjacent layers are in contact but also facilitating the sample dispersion. With these outstanding characteristics, our platform obtained a satisfactory sensitivity range from 3 × 10⁵ to 3 × 10⁸ copies with a limit of 3 × 10⁶ copies. Additionally, the multiplex small RNA analyses from various cancer cells were in good agreement with the results of the real-time polymerase chain reaction (qRT-PCR). More importantly, simultaneous analysis of two types of miRNAs from clinical tumor samples demonstrated the clinical applicability of the system. Therefore, the proposed paper-based device shows great promise for POC applications in the future.

中文翻译：

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用于小RNA提取，扩增和多重分析的Paperfluidic芯片设备

小RNA被认为是各种人类疾病的潜在生物标记。即时点（POC）检测灵敏和多重测定小RNA具有重要意义。在此，首次开发了用于多重小RNA分析的集成纸流芯片装置。在该系统中，小RNA的提取和纯化通过聚醚砜（PES）纸屑完成，无需离心。随后，在提取纸屑中直接进行了新设计的发夹探针-指数扩增反应（HP-EXPAR）。为了同时实现多重检测，以可折叠的方式设计了多层纸芯片，其具有更大的便携性和可用性。量子点（QD）被用作信号标记，从而使该测定具有很高的光学检测效率。此外，引入磁性片材作为用于层堆叠的替代方法，不仅确保相邻层接触，而且还促进了样品的分散。凭借这些出色的特性，我们的平台获得了3×10的满意灵敏度范围⁵至3×10 ⁸份，限制为3×10 ⁶份。此外，来自各种癌细胞的多重小RNA分析与实时聚合酶链反应（qRT-PCR）的结果非常吻合。更重要的是，对来自临床肿瘤样本的两种类型的miRNA的同时分析证明了该系统的临床适用性。因此，所提出的基于纸张的设备在未来的POC应用中显示出了广阔的前景。