Abstract：
Target-responsive aptamer hydrogels are increasingly used in the field of analytical sensing with different morphologies developed by various strategies. Herein, we developed a DNA hydrogel film combined with capillary self-driven action for the specific detection of the tumor marker EpCAM and further introduced Exo I for signal amplification. EpCAM aptamer was used as a crosslinking agent to construct the DNA hydrogel film. When EpCAM was present, it competed for binding with the EpCAM aptamer, resulting in a permeability change of the DNA hydrogel film attached to one end of the capillary, and leading to different solution flow rates through the capillaries that can be utilized for the quantitative detection of EpCAM. This method did not require any instrument and was easy to use. The distance the solution travelled through the capillary was quantified as the concentration of EpCAM, and only a small amount of DNA hydrogel was required for each detection. The detection limit of EpCAM was as low as 0.018 ng mL-1, while offering the advantages of good stability and specificity, and showing great potential in point-of-care testing.
摘要：
目标响应性适体水凝胶越来越多地用于通过各种策略开发的具有不同形态的分析传感领域。在这里，我们开发了一种结合毛细管自驱动作用的DNA水凝胶膜，用于特异性检测肿瘤标志物EpCAM，并进一步引入ExoI用于信号放大。使用EpCAM适体作为交联剂来构建DNA水凝胶膜。当EpCAM出现时,它竞争与EpCAM适体的结合，导致附着在毛细管一端的DNA水凝胶膜的渗透性变化，并导致通过毛细管的不同溶液流速，可用于EpCAM的定量检测。该方法不需要任何仪器并且易于使用。将溶液通过毛细管的距离量化为EpCAM的浓度，每次检测只需要少量的DNA水凝胶。EpCAM的检出限低至0.018ngmL-1,同时具有良好的稳定性和特异性,并在即时测试中显示出巨大的潜力。
