Department of Science and Technology, Qufu Normal University, Qufu City 273165, Shandong, China; Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu City 273165, Shandong, China.
Key Laboratory of Catalytic Conversion and Clean Energy in Universities of Shandong Province, School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu City 273165, Shandong, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jul 5;295:122620. doi: 10.1016/j.saa.2023.122620. Epub 2023 Mar 11.
A novel ratiometric fluorescence strategy for sulfide ions (S) analysis has been developed using metal-organic framework (MOF)-based nanozyme. NH-Cu-MOF displays blue fluorescence (λem = 435 nm) originating from 2-amino-1,4-benzenedicarboxylic acid ligand. Besides, it possesses oxidase-like activity due to Cu node, which can trigger chromogenic reaction. o-Phenylenediamine (OPD), as a common enzyme substrate, can be oxidized by NH-Cu-MOF to form luminescent products (oxOPD) (λem = 570 nm). Inner filter effect occurs between oxOPD and MOF. Upon exposure to S, oxidase-like activity of MOF is depressed significantly because of the generation of CuS. On one hand, the amount of free Cu decreases, affecting the yielding of oxOPD. On the other hand, CuNPs with larger size are obtained during the oxidation-reduction reaction between Cu and OPD, which show weaker autocatalytic ability for OPD oxidation. These result in the decrease and increase of intensities at 570 and 435 nm, respectively. This method exhibits sensitive and selective responses towards S with LOD of 0.1 μM. Furthermore, such ratiometric strategy has been applied to detect S in food samples.
一种基于金属-有机骨架（MOF）纳米酶的新型硫化物（S）比率荧光分析策略已经被开发出来。NH-Cu-MOF 呈现蓝色荧光（λem = 435nm），源于 2-氨基-1,4-苯二甲酸配体。此外，由于 Cu 节点，它具有氧化酶样活性，可以引发显色反应。邻苯二胺（OPD）作为一种常见的酶底物，可以被 NH-Cu-MOF 氧化形成发光产物（oxOPD）（λem = 570nm）。oxOPD 和 MOF 之间存在内滤效应。当暴露于 S 时，MOF 的氧化酶样活性由于 CuS 的生成而显著降低。一方面，游离的 Cu 减少，影响 oxOPD 的生成。另一方面，在 Cu 和 OPD 之间的氧化还原反应中得到较大尺寸的 CuNPs，它们对 OPD 氧化的自催化能力较弱。这导致在 570nm 和 435nm 处的强度分别降低和增加。该方法对 S 具有敏感和选择性响应，LOD 为 0.1μM。此外，这种比率策略已被应用于检测食品样品中的 S。
