Zhao Fan, Liu Yunxi, Lan Jingyue
Tianjin Key Laboratory of Structure and Performance for Functional Molecules, College of Chemistry, Tianjin Normal University, Tianjin, 300387, China.
Mikrochim Acta. 2024 Aug 27;191(9):564. doi: 10.1007/s00604-024-06626-4.
A simple and efficient dual-signal electrochemical sensor was designed for glyphosate (GLYP) determination based on the one-step electro-synthesized Cu-Hemin MOFs/CNTs nanocrystals. Cu-Hemin MOFs/CNTs were directly modified on the electrode through electrodeposition, avoiding complicated synthesis and modification processes. The incorporation of CNTs greatly boosted the conductivity of Cu-Hemin MOFs and the sensitivity of the electrochemical sensor. Cu active sites in Cu-Hemin MOFs were converted to CuCl, allowing the specific detection of GLYP with the turn of CuCl into non-electroactive Cu-GLYP. Meanwhile, GLYP showed highly effective inhibition effect on the inherent peroxidase-like activity of Cu-Hemin MOFs, therefore generating the second electrochemical signal with Cu-Hemin MOFs-catalyzed o-phenylenediamine (o-PD) + HO system. The Cu-Hemin MOFs/CNTs based sensor with two electrochemical signals showed good linearities of 1.0 × 10 M - 3.0 × 10 M and 1.0 × 10 M - 5.0 × 10 M, with detection limits of 5.17 × 10 M and 6.81 × 10 M for the CuCl signal based assay and nanozyme catalyzed o-PD + HO procedure, respectively. This simple and robust dual-signal sensor with excellent selectivity, accuracy, and stability allowed GLYP quantification in real samples, highlighting the potential application of this approach for food and environmental monitoring.
基于一步电合成的铜-血红素金属有机框架/碳纳米管（Cu-Hemin MOFs/CNTs）纳米晶体，设计了一种简单高效的双信号电化学传感器用于草甘膦（GLYP）的测定。通过电沉积将Cu-Hemin MOFs/CNTs直接修饰在电极上，避免了复杂的合成和修饰过程。碳纳米管的引入极大地提高了Cu-Hemin MOFs的导电性和电化学传感器的灵敏度。Cu-Hemin MOFs中的铜活性位点转化为氯化铜（CuCl），通过将CuCl转化为非电活性的铜-草甘膦（Cu-GLYP）实现对GLYP的特异性检测。同时，GLYP对Cu-Hemin MOFs固有的过氧化物酶样活性表现出高效抑制作用，因此在Cu-Hemin MOFs催化邻苯二胺（o-PD）+H₂O₂体系中产生第二个电化学信号。基于Cu-Hemin MOFs/CNTs的具有两个电化学信号的传感器在1.0×10⁻⁹ M - 3.0×10⁻⁷ M和1.0×10⁻⁷ M - 5.0×10⁻⁶ M范围内呈现良好的线性关系，基于CuCl信号检测法和纳米酶催化o-PD+H₂O₂法的检测限分别为5.17×10⁻¹⁰ M和6.81×10⁻¹⁰ M。这种简单且稳健的具有优异选择性、准确性和稳定性的双信号传感器能够对实际样品中的GLYP进行定量分析，突出了该方法在食品和环境监测中的潜在应用价值。
