State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science of Guangxi Normal University, Guilin, 541004, PR China.
State Key Laboratory for the Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Science of Guangxi Normal University, Guilin, 541004, PR China.
Biosens Bioelectron. 2023 Oct 1;237:115542. doi: 10.1016/j.bios.2023.115542. Epub 2023 Jul 20.
Most current redox-type nanozyme-based colorimetric sensing platforms are susceptible to interference from the reductant when using chromogenic probe, and the unstable HO used in the peroxidase-like nanozyme-based systems is prone to difficulty in sensing signal reproducibility, while peroxidase-like nanozyme with oxidase-mimicking activity is easy to bring background interference by O. Since the strong structural designability of covalent organic frameworks (COFs) endows them great application value in the sensing fields, therefore, we envision the construction a COF oxidase-like nanozyme-based controllable sensing system that integrates self-reporting, self-correcting and light-responsive functions to avoid these affects. Herein, 3-nitrotyrosine (3-NT) biomarker was selected as model analyte. 1,3,5-triformylphloroglucinol (Tp) and 3,6-diaminoacridine (DA) were acted as building monomers of the multifunctional COF nanozyme (termed as TpDA). Owing to the excellent light-responsive oxidase-mimicking property of TpDA, 3-NT can be efficiently oxidized, the inner filter effect (IFE) between TpDA and the 3-NT oxidation product greatly quenches the intrinsic fluorescence of TpDA, making it a controllable self-reporting system for fluorescence turn-off sensing 3-NT. Additionally, the excessive reactive oxygen species (ROS) that generated continuously during photocatalysis can resist the interference of endogenous reductants. This study not only provides new insights to avoid the interference of HO, background and reductants from conventional redox-type nanozyme-based colorimetric systems but also opens avenues to rational construct versatile COF nanozyme-based sensor.
大多数基于还原型纳米酶的比色传感平台在使用显色探针时容易受到还原剂的干扰，而过氧化物酶模拟纳米酶体系中不稳定的 HO 容易导致传感信号重现性困难，而具有氧化酶模拟活性的过氧化物酶模拟纳米酶容易带来 O 的背景干扰。由于共价有机框架（COFs）的强结构设计性赋予了它们在传感领域的巨大应用价值，因此，我们设想构建一种基于 COF 氧化酶样纳米酶的可控传感系统，该系统集成了自报告、自校正和光响应功能，以避免这些影响。在这里，选择 3-硝基酪氨酸（3-NT）生物标志物作为模型分析物。1,3,5-均苯三甲醛（Tp）和 3,6-二氨基吖啶（DA）分别作为多功能 COF 纳米酶的构筑单体（称为 TpDA）。由于 TpDA 具有优异的光响应氧化酶模拟特性，3-NT 可以被有效地氧化，TpDA 和 3-NT 氧化产物之间的内滤效应（IFE）大大猝灭了 TpDA 的固有荧光，使其成为一种用于荧光关闭传感 3-NT 的可控自报告系统。此外，光催化过程中不断产生的过量活性氧物种（ROS）可以抵抗内源性还原剂的干扰。本研究不仅为避免传统基于还原型纳米酶的比色系统中 HO、背景和还原剂的干扰提供了新的思路，而且为合理构建多功能 COF 纳米酶基传感器开辟了途径。
