Department of Chemistry and Biochemistry, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968, United States.
Biomedical Engineering, The University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968, United States.
Anal Chem. 2020 May 19;92(10):7045-7053. doi: 10.1021/acs.analchem.0c00317. Epub 2020 Apr 30.
Glass slides have been widely used for DNA immobilization in DNA microarray and numerous bioassays for decades, whereas they are faced with limitations of low probe density, time-consuming modification steps, and expensive instruments. In this work, a simple one-step surface modification method using 3-aminopropyl trimethoxysilane (APTMS) has been developed and applied to graft DNA codes on paper. Higher DNA immobilization efficiency was obtained in comparison with that in a conventional method using glass slides. Fluorescence detection, X-ray photoelectron spectroscopy (XPS), infrared spectra (FT-IR), and pH influence studies were employed to characterize the surface modification and subsequent DNA immobilization, which further reveals a mechanism in which this method lies in ionic interactions between the positively charged APTMS-modified paper surface and negatively charged DNA probes. Furthermore, an APTMS-modified paper-based device has been developed to demonstrate application in low-cost detection of a foodborne pathogen, , with high sensitivity (the detection limit of 22 nM) and high specificity. Compared with conventional methods using redundant cross-linking reactions, our method is simpler, faster, versatile, and lower-cost, enabling broad applications of paper-based bioassays especially for point-of-care detection in resource-poor settings.
几十年来，载玻片一直被广泛应用于 DNA 微阵列和众多生物测定中以固定 DNA，但它也面临着探针密度低、修饰步骤繁琐和仪器昂贵等局限性。在这项工作中，开发了一种简单的一步法表面修饰方法，使用 3-氨丙基三甲氧基硅烷（APTMS），并将其应用于纸张上的 DNA 码接枝。与使用载玻片的传统方法相比，获得了更高的 DNA 固定化效率。荧光检测、X 射线光电子能谱（XPS）、红外光谱（FT-IR）和 pH 值影响研究用于对表面修饰和随后的 DNA 固定化进行表征，这进一步揭示了该方法的机制在于带正电荷的 APTMS 修饰的纸张表面与带负电荷的 DNA 探针之间的离子相互作用。此外，还开发了一种基于 APTMS 修饰的纸张设备，用于展示在低成本检测食源性病原体中的应用，具有高灵敏度（检测限为 22 nM）和高特异性。与使用冗余交联反应的传统方法相比，我们的方法更简单、更快、更通用且成本更低，使基于纸张的生物测定得到广泛应用，特别是在资源匮乏环境中的即时检测。
