Jiang Xianrui, Yao Tao, Shi Xingxin, Han Hongliang, Ma Zhanfang
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Department of Chemistry, Capital Normal University, Beijing 100048, China.
Colloids Surf B Biointerfaces. 2025 Jan;245:114331. doi: 10.1016/j.colsurfb.2024.114331. Epub 2024 Oct 22.
Rational design and tailoring of the surface microenvironment surrounding the catalytic sites, such as noble metal nanoparticles, is an effective way to enhance the catalytic activity of mimicking enzymes. However, it remains on-going challenges to regulate the microenvironment of the catalytic sites due to the lack of tunable variability in structural precision of conventional solid catalysts. Herein, three types of zeolitic imidazolate framework-8 (ZIF-8) with different major crystal facet orientations, i.e., cubic with (100) facets (denoted ZIF-8), truncated dodecahedral with (100), (110) facets (denoted ZIF-8), and dodecahedral with (110) facets (denoted ZIF-8), were developed facilely using an electrochemical method by switching the potential at ambient temperature. Because the Zn nodes were predominantly exposed on the (100) facets of ZIF-8, while the ligands were mainly exposed on the (110) facets. Hence, gold nanoparticles (AuNPs) showed differential glucose oxidase (GOx)-like activities when anchored in situ on different crystal facets of ZIF-8 and obeyed the following order ZIF-8/Au>ZIF-8/Au>ZIF-8/Au. Notably, both the metal nodes and aromatic linkers of ZIF-8 interacted with AuNPs through coordination and π-π interactions. The Zn nodes facilitated the formation of the electron-deficient Au species. The electron transfer from AuNPs to Zn sites effectively boosted the catalytic activity. It was known that directly tailoring the microenvironment at the supporting sites of noble metal catalysts to boost catalysis through a facile electrochemical method was not reported. Based on the favorable GOx-like activity and long-term stability of ZIF-8/Au, a highly sensitive electrochemical biosensing platform for assaying squamous cell carcinoma antigen (SCCA) was developed. It enabled fg-level detection of cancer marker.
合理设计和定制催化位点周围的表面微环境，如贵金属纳米颗粒，是提高模拟酶催化活性的有效方法。然而，由于传统固体催化剂在结构精度上缺乏可调变性，调节催化位点的微环境仍然面临挑战。在此，通过在室温下切换电位，采用电化学方法简便地制备了三种具有不同主要晶面取向的沸石咪唑酯骨架-8（ZIF-8），即具有（100）面的立方体（记为ZIF-8）、具有（100）、（110）面的截角十二面体（记为ZIF-8）和具有（11）面的十二面体（记为ZIF-8）。因为锌节点主要暴露在ZIF-8的（100）面上，而配体主要暴露在（110）面上。因此，金纳米颗粒（AuNPs）原位锚定在ZIF-8的不同晶面上时表现出不同的葡萄糖氧化酶（GOx）样活性，且遵循以下顺序：ZIF-8/Au>ZIF-8/Au>ZIF-8/Au。值得注意的是，ZIF-8的金属节点和芳香连接体都通过配位和π-π相互作用与AuNPs相互作用。锌节点促进了缺电子金物种的形成。从AuNPs到锌位点的电子转移有效地提高了催化活性。据了解，尚未有通过简便的电化学方法直接定制贵金属催化剂支撑位点的微环境以促进催化作用的报道。基于ZIF-8/Au良好的GOx样活性和长期稳定性，开发了一种用于检测鳞状细胞癌抗原（SCCA）的高灵敏度电化学生物传感平台。它能够实现癌症标志物的飞克级检测。
