Laboratory of Biosensors and Bioelectronics, Institute for Biomedical Engineering , ETH Zurich , 8092 Zurich , Switzerland.
ACS Sens. 2019 Jul 26;4(7):1950-1956. doi: 10.1021/acssensors.9b00946. Epub 2019 Jul 16.
MicroRNA (miRNA) is a class of short RNA that is emerging as an ideal biomarker, as its expression level has been found to correlate with different types of diseases including diabetes and cancer. The detection of miRNA is highly beneficial for early diagnostics and disease monitoring. However, miRNA sensing remains difficult because of its small size and low expression levels. Common techniques such as quantitative real-time polymerase chain reaction (qRT-PCR), hybridization and Northern blotting have been developed to quantify miRNA in a given sample. Nevertheless, these methods face common challenges in point-of-care practice as they either require complicated sample handling and expensive equipment, or suffer from low sensitivity. Here we present a new tool based on dark-field microwells to overcome these challenges in miRNA sensing. This miniaturized device enables the readout of a gold nanoparticle assay without the need of a dark-field microscope. We demonstrate the feasibility of the dark-field microwells to detect miRNA in both buffer solution and cell lysate. The dark-field microwells allow affordable miRNA sensing at a high throughput which make them a promising tool for point-of-care diagnostics.
微 RNA（miRNA）是一类短 RNA，作为理想的生物标志物正在崭露头角，因为其表达水平与包括糖尿病和癌症在内的不同类型的疾病相关。miRNA 的检测对于早期诊断和疾病监测非常有益。然而，由于 miRNA 体积小、表达水平低，其检测仍然很困难。已经开发出定量实时聚合酶链反应（qRT-PCR）、杂交和 Northern 印迹等常见技术来定量给定样本中的 miRNA。然而，由于这些方法要么需要复杂的样本处理和昂贵的设备，要么存在灵敏度低的问题，因此在即时护理实践中面临共同的挑战。在这里，我们提出了一种基于暗场微井的新工具，以克服 miRNA 传感中的这些挑战。这种微型化装置可以在不需要暗场显微镜的情况下读取金纳米粒子检测结果。我们证明了暗场微井在缓冲液和细胞裂解物中检测 miRNA 的可行性。暗场微井可以以较高的通量进行经济实惠的 miRNA 检测，这使它们成为即时护理诊断的有前途的工具。
