School of Chemistry and Environment, Southwest Minzu University, Chengdu, 610041, China.
School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China.
J Nanosci Nanotechnol. 2021 Dec 1;21(12):6126-6134. doi: 10.1166/jnn.2021.19533.
Nanomaterials with intrinsic enzyme-mimicking characteristics, refered to as nanozymes, have become a hot research topic owing to their unique advantages of comparative low cost, high stability and large-scale preparation. Among them, Single-atom nanozymes (SAzymes), as novel nanozymes with abundant atomically dispersed active sites, have caused specific attention in the development of nanozymes for their remarkable catalytic activities, maximum atomic utilization and excellent selectivity, the homogeneous catalytic sites and clear catalytic mechanisms. Herein, a novel single-atom nanozyme based on Fe(III)-doped polydiaminopyridine nanofusiforms (Fe-PDAP SAzyme) was successfully proposed via facile oxidation polymerization strategy. With well-defined coordination structure and abundant Fe-Nx active sites similar to natural metalloproteases, the Fe-PDAP SAzyme exhibits superior peroxidase-like activity by efficiently decomposing H₂O₂ for hydroxyl radical (.OH) species formation. Based on their superior peroxidase-like activity, colorimetric biosensing of H₂O₂ and glucose was performed by using a typical 3,3,5,5-tetramethylbenzidine through a multienzyme biocatalytic cascade platform, exhibiting the superior specificity and sensitivity. This work not only provides a novel promising SAzyme-based biosensor but also paves an avenue for evaluating enzyme activity and broadens the application of other nanozyme-based biosensors in the fields of biomedical diagnosis.
具有内在酶模拟特性的纳米材料，称为纳米酶，由于其成本相对较低、稳定性高和大规模制备等独特优势，成为了一个热门的研究课题。其中，单原子纳米酶（SAzymes）作为具有丰富原子分散活性位的新型纳米酶，因其显著的催化活性、最大的原子利用率和优异的选择性、均相催化位和明确的催化机制而在纳米酶的发展中引起了特别关注。本文中，通过简便的氧化聚合策略，成功提出了一种基于 Fe(III)掺杂聚二氨基吡啶纳米纤维（Fe-PDAP SAzyme）的新型单原子纳米酶。具有明确的配位结构和丰富的类似于天然金属蛋白酶的 Fe-Nx 活性位，Fe-PDAP SAzyme 通过高效分解 H₂O₂生成羟基自由基（.OH）物种，表现出优异的过氧化物酶样活性。基于其优异的过氧化物酶样活性，通过使用典型的 3,3,5,5-四甲基联苯胺，通过多酶生物催化级联平台对 H₂O₂和葡萄糖进行比色生物传感，表现出优异的特异性和灵敏度。这项工作不仅提供了一种新型有前途的基于 SAzyme 的生物传感器，而且为评估酶活性开辟了一条途径，并拓宽了其他基于纳米酶的生物传感器在生物医学诊断领域的应用。
