Metal-based enzyme-mimetic biocatalysts exhibit much better enzyme-like activity than metal-free biocatalysts. At the same time, both non-noble and noble metal-based catalysts have been proven to exhibit good biocatalytic activity. It is a great challenge to find extremely sensitive and adaptable biosensors with biocatalytic activity in biotechnology and medical diagnostics. For performance improvement and cost reduction, the development of non-noble metal-based biocatalysts is still of great significance. Here, we disclose that the covalent organic frameworks (COFs) coordinated by cobalt (Co) or nickel (Ni) with specific oxidase-like (OXD-like) activities can serve as intelligent artificial enzymes for light-augmented biocatalytic sensing of biomarkers. Because of the effects of metallic elements on the band gap adjustment, the Ni–COF exhibited the most efficient, selective, and light-responsive OXD-like biocatalytic activity (K = 0.91 mM, V = 1.50 μM s). Moreover, COFs loading metals show superior light-augmented biocatalytic detection capabilities. Notably, Ni–COF exhibits the most efficient and multifaceted diagnostic activity, including the extremely low limit of detection (LOD): 0.34 μM for glutathione and 0.54 μM for -cysteine, which enables visual assays for abundant reducibility biomarkers. This study offers a unique and efficient non-noble metal-coordinated COF biocatalyst for high-sensitive and low-cost colorimetric detection. It also provides new insights into the design of non-noble metal elements in COF materials with better enzyme-like activities in biocatalytic and biomedical applications.

中文翻译：

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非贵金属配位共价有机骨架作为类氧化酶生物催化剂用于光响应生物标志物传感

金属基模拟酶生物催化剂比不含金属的生物催化剂表现出更好的类酶活性。同时，非贵金属基催化剂和贵金属基催化剂均已被证明表现出良好的生物催化活性。在生物技术和医学诊断中寻找具有生物催化活性的极其灵敏和适应性强的生物传感器是一个巨大的挑战。对于性能提升和成本降低，开发非贵金属基生物催化剂仍然具有重要意义。在这里，我们公开了由具有特定氧化酶样（OXD样）活性的钴（Co）或镍（Ni）协调的共价有机框架（COF）可以作为智能人工酶，用于生物标志物的光增强生物催化传感。由于金属元素对带隙调节的影响，Ni-COF表现出最高效、选择性和光响应性的类OXD生物催化活性（K = 0.91 mM，V = 1.50 μM s）。此外，负载金属的COF表现出卓越的光增强生物催化检测能力。值得注意的是，Ni-COF 表现出最有效和多方面的诊断活性，包括极低的检测限 (LOD)：谷胱甘肽为 0.34 μM，半胱氨酸为 0.54 μM，从而可以对丰富的还原性生物标志物进行可视化分析。这项研究提供了一种独特且高效的非贵金属配位COF生物催化剂，用于高灵敏度和低成本的比色检测。它还为 COF 材料中非贵金属元素的设计提供了新的见解，在生物催化和生物医学应用中具有更好的类酶活性。