Tong Yao, Yang Jian, Xia Fan, Gu Jinlou
Key Lab for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
JACS Au. 2024 Dec 31;5(1):178-186. doi: 10.1021/jacsau.4c00866. eCollection 2025 Jan 27.
The creation of spatially coupled meso-/microenvironments with biomimetic compartmentalized functionalities is of great significance to achieve efficient signal transduction and amplification. Herein, using a soft-template strategy, UiO-67-type hierarchically mesoporous metal-organic frameworks (HMMOFs) were constructed to satisfy the requirements of such an artificial system. The key to the successful synthesis of HMUiO-67 is rooted in the utilization of the preformed cerium-oxo clusters as metal precursors, aligning the growth of MOF crystals with the mild conditions required for the self-assembly of the soft template. The adoption of long-chain functional 2,2'-bipyridine-5,5'-dicarboxylic acid ligands not only resulted in larger microporous sizes, facilitating the transport of various cascade reaction intermediates, but also provided anchorages for the introduction of enzyme-mimicking active sites. A cascade amplification system was designed based on the developed HMUiO-67, in which enzyme cascade reactions were initiated and relayed by a target analyte in the separate but coupled meso/micro spaces. As a proof of concept, natural acetylcholinesterase (AChE) and Cu-based laccase mimetics were integrated into HMMOFs, establishing a spatially coupled nanoreactor. The activity of AChE was triggered by the target analyte of carbaryl, while the amplified products of AChE catalysis mediated the activity of biomimetic enzyme in the closely proximate microporous spaces, producing further amplification of detectable signal. This enabled the entire cascade system to respond to minimal carbaryl with a limit of detection as low as approximately 2 nM. Such a model of cascade amplification is expected to set a conceptual guideline for the rational design of various bioreactors, serving as a sensitive response system for quantifying numerous target analytes.
创建具有仿生分区功能的空间耦合中观/微观环境对于实现高效的信号转导和放大具有重要意义。在此,采用软模板策略构建了UiO-67型分级介孔金属有机框架(HMMOFs),以满足这种人工系统的要求。成功合成HMUiO-67的关键在于利用预先形成的铈氧簇作为金属前驱体,使MOF晶体的生长与软模板自组装所需的温和条件相一致。采用长链功能性2,2'-联吡啶-5,5'-二羧酸配体不仅导致更大的微孔尺寸,有利于各种级联反应中间体的传输,还为引入模拟酶活性位点提供了锚固点。基于所开发的HMUiO-67设计了一种级联放大系统,其中酶级联反应由目标分析物在单独但耦合的中观/微观空间中引发和中继。作为概念验证将天然乙酰胆碱酯酶(AChE)和铜基漆酶模拟物整合到HMMOFs中,建立了一个空间耦合的纳米反应器。AChE的活性由西维因目标分析物触发,而AChE催化的放大产物介导了紧邻微孔空间中仿生酶的活性,产生可检测信号的进一步放大。这使得整个级联系统能够对最低限度的西维因做出响应,检测限低至约2 nM。这种级联放大模型有望为各种生物反应器的合理设计提供概念指导,作为定量众多目标分析物的灵敏响应系统。