Abstract：
The residues of organophosphorus pesticides (OPs) are increasing environmental pollution and public health concerns. Thus, the development of simple, convenient and sensitive method for detection of OPs is crucial. Herein, a multifunctional Fe-based MOF with fluorescence, catalytic and adsorption, is synthesized by a simple one-pot hydrothermal method. The ratiometric fluorescence sensor for detection of OPs is constructed by using only one multifunctional sensing material. The NH2-MIL-101(Fe) is able catalyze the o-phenylenediamine (OPD) into 2,3-diaminophenazine (DAP) in the presence of H2O2. The generated DAP can significantly quench the intrinsic fluorescence of NH2-MIL-101(Fe) by the fluorescence resonance energy transfer (FRET) and internal filtration effect (IFE), while producing a new measurable fluorescence. Without immobilization or molecular imprinting, pyrophosphate ion (PPi) can inhibit the peroxidase-like activity of the NH2-MIL-101(Fe) by chelating with Fe3+/Fe2+ redox couple. Moreover, PPi can also be hydrolyzed by alkaline phosphatase (ALP), the presence of OPs inhibits the activity of ALP, resulting in the increase of extra PPi preservation and signal changes of ratiometric fluorescence, the interactions of ALP with different OPs are explored by molecular docking, the OPs (e.g., glyphosate) interact with crucial amino acid residues (Asp, Ser, Ala, Lys and Arg) are indicated. The proposed sensor exhibits excellent detection performance for OPs with the detection limit of 18.7 nM, which provides a promising strategy for detection of OPs.
摘要：
有机磷农药（OPs）的残留正在增加环境污染和公共卫生问题。因此，简单的发展，简便、灵敏的OPs检测方法至关重要。在这里，具有荧光的多功能铁基MOF，催化和吸附，通过简单的一锅法合成。仅使用一种多功能传感材料构建了用于检测OPs的比率荧光传感器。NH2-MIL-101（Fe）能够在H2O2存在下将邻苯二胺（OPD）催化成2,3-二氨基苯并嗪（DAP）。所产生的DAP可以通过荧光共振能量转移(FRET)和内部过滤效应(IFE)显著猝灭NH2-MIL-101(Fe)的固有荧光,同时产生新的可测量的荧光。没有固定或分子印迹，焦磷酸离子（PPi）可以通过与Fe3/Fe2氧化还原对螯合来抑制NH2-MIL-101（Fe）的过氧化物酶样活性。此外，PPi也可以被碱性磷酸酶（ALP）水解，OPs的存在抑制了ALP的活性，导致额外的PPi保存和比率荧光信号变化的增加，通过分子对接探索ALP与不同OPs的相互作用，OPs(例如，草甘膦）与关键氨基酸残基（Asp，Ser,阿拉,示出了Lys和Arg)。所提出的传感器对OPs表现出优异的检测性能，检测极限为18.7nM，这为OPs的检测提供了一种有前途的策略。
