Al Sulaiman Dana, Shapiro Sarah J, Gomez-Marquez Jose, Doyle Patrick S
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
Little Devices Lab, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.
ACS Sens. 2021 Jan 22;6(1):203-211. doi: 10.1021/acssensors.0c02121. Epub 2020 Dec 22.
There has been an increasing and urgent demand to develop nucleic acid bioassays which not only offer high analytical performance but which are also amenable with point-of-care testing. Hydrogels present a versatile class of materials with biocompatible antifouling properties and the ability to be engineered for a range of advanced sensing applications. Fibrous substrates like nitrocellulose offer low-cost and durable platforms to run complex bioassays while enabling portability and ease of handling. We demonstrate herein the ability to synergistically combine these two materials into a portable biosensing platform by leveraging projection lithography. We demonstrate the direct polymerization of hydrogel sensing motifs within a range of fibrous substrates with precise control over their shape, size, location, and functionality. Spatial encoding of the hydrogel motifs enables the multiplex detection of multiple biomarkers on the same test. As a proof-of-concept, we apply the platform to the detection of microRNA, an emerging class of circulating biomarkers with promising potential for early diagnosis and monitoring of cancer. The assay offers a large dynamic range (over three orders of magnitude), high sensitivity (limit of detection of 2.5 amol), as well as versatility and ease of handling. Finally, the bioassay is validated using real biological samples, namely, total RNA extracted from the sera of late-stage breast cancer patients, demonstrating its utility and compatibility with clinical biosensing applications.
开发不仅具有高分析性能而且适用于即时检测的核酸生物测定法的需求日益增长且迫切。水凝胶是一类具有生物相容性防污特性且能够设计用于一系列先进传感应用的多功能材料。像硝酸纤维素这样的纤维基质提供了低成本且耐用的平台来进行复杂的生物测定，同时具备便携性和易于操作的特点。我们在此展示了通过利用投影光刻技术将这两种材料协同结合成一个便携式生物传感平台的能力。我们展示了在一系列纤维基质内水凝胶传感基序的直接聚合，并对其形状、尺寸、位置和功能进行精确控制。水凝胶基序的空间编码能够在同一测试中对多种生物标志物进行多重检测。作为概念验证，我们将该平台应用于检测微小RNA，这是一类新兴的循环生物标志物，在癌症的早期诊断和监测方面具有广阔前景。该测定法具有大动态范围（超过三个数量级）、高灵敏度（检测限为2.5 amol）以及多功能性和易于操作性。最后，使用实际生物样本，即从晚期乳腺癌患者血清中提取的总RNA对该生物测定法进行了验证，证明了其在临床生物传感应用中的实用性和兼容性。
