Enzyme-based hydrogels have conferred multiple benefits, particularly for disease diagnosis and environmental monitoring due to their pronounced biocompatibility, ability to load cargo, and optical properties. However, traditional hydrogels suffer from some significant limitations, such as enzyme leakage and catalytic activity decreased, restricting the extent to which hydrogels can be beneficially used. Herein, chemically programmed DNA-DNA interactions were designed as a promising solution for enzyme immobilization that substantially maintains biological functionality with remarkable leakage reduction. Additionally, their responsiveness and mechanical properties are dramatically enhanced after adjusting the porous structure of hydrogels via freezing. As a proof-of-concept, a DNA cryogel with a hierarchical structure was developed with adjustable distance among cascade enzymes, increasing the local concentration of intermediates and reducing their mass transfer energy barriers for direct glucose monitoring and glutathione (GSH) sensing. Moreover, after being integrated with a smartphone system, a universal sensing platform (immunosensor) was fabricated for rapid detection of environmental chemicals (i.e., bisphenol A) without expensive instruments and sophisticated procedures. This strategy provided some novel insights on hydrogel- based bioassays, implying their great potentials for conducting onsite analysis against various targets.

中文翻译：

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双网络结构化学编程 DNA Cryogel：具有增强催化活性的酶固定平台，适用于便携式生物传感

基于酶的水凝胶具有多种益处，特别是在疾病诊断和环境监测方面，因为它们具有明显的生物相容性、装载货物的能力和光学特性。然而，传统的水凝胶存在一些明显的局限性，例如酶泄漏和催化活性下降，限制了水凝胶的有益使用程度。在此，化学编程的 DNA-DNA 相互作用被设计为一种有前途的酶固定解决方案，可基本上保持生物功能并显着减少泄漏。此外，通过冷冻调整水凝胶的多孔结构后，它们的响应能力和机械性能显着增强。作为概念验证，开发了一种具有分层结构的 DNA 冷冻凝胶，其级联酶之间的距离可调，增加了中间体的局部浓度并减少了其传质能量障碍，用于直接葡萄糖监测和谷胱甘肽 (GSH) 传感。此外，与智能手机系统集成后，构建了通用传感平台（免疫传感器），无需昂贵的仪器和复杂的程序即可快速检测环境化学物质（即双酚A）。该策略为基于水凝胶的生物测定提供了一些新颖的见解，这意味着它们在针对各种目标进行现场分析方面具有巨大的潜力。