Background

Atrazine (ATZ), a pesticide that poses serious health problems, is observed in the environment, thereby prompting its periodic monitoring and control using functional biosensors. However, established methods for ATZ detection have limited applicability. Two-dimensional (2D) metal azolate frameworks (MAF) have a higher surface area per unit volume and provide easier access to active sites. The shorter diffusion path for guest molecules increases the diffusion rates, which is suitable for electrochemical detection. The sensing performance of electrochemical biosensors can be improved by modifying MAFs, resulting in their high affinity for highly sensitive and selective detection of ATZ in the environment.

Results

Cu/Zr-based MAF synthesized via a simple sonochemical method and surface-engineered ozonation are demonstrated for the electrochemical sensing of ATZ. The combination of ultrasonication and ultraviolet/ozone surface functionalization significantly enhance the properties of a two-dimensional MAF, including a reduction in resistance, an increase in specific surface area, and the creation of numerous active sites. The developed electrochemical biosensors exhibit a high sensitivity (8.8 μA μM^-1 cm^-2), low detection limit of 0.236 zM, and wide linear range of 1 zM to 1 M towards ATZ. Furthermore, excellent selectivity in the presence of diverse interferents and a long shelf life in ambient air for 60 d are achieved. The practical feasibility of the biosensor consisting of surface-engineered Cu/Zr-MAF is demonstrated by detecting the ATZ in agricultural wastewater and river water.

Significance and Novelty

Cu and Zr transition metals with multiple valence states in MAF facilitate the reduction of ATZ through coordination bonding, while the increased oxygenating active sites in 2D structure collectively accelerates the charge transfer. This synergy between the structural design and surface engineering ultimately improves the biosensor's sensitivity and efficiency for the detection of ATZ. This work can provide a new perspective on practical biosensor applications for the electrochemical detection of pesticides at extremely low concentrations.

中文翻译：

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Cu/Zr 金属偶氮酸盐框架的合成后表面改性：用于阿特拉津检测的高灵敏度电化学生物传感器的途径

 背景

阿特拉津 （ATZ） 是一种会造成严重健康问题的杀虫剂，在环境中被观察到，因此促使使用功能性生物传感器对其进行定期监测和控制。然而，已建立的 ATZ 检测方法的适用性有限。二维 （2D） 金属偶氮酸盐框架 （MAF） 具有更高的单位体积表面积，并且更容易进入活性位点。客体分子的较短扩散路径增加了扩散速率，这适用于电化学检测。通过修饰 MAFs，可以提高电化学生物传感器的传感性能，使其对环境中 ATZ 的高灵敏度和选择性检测具有很高的亲和力。

 结果

通过简单的声化学方法和表面工程臭氧化合成的 Cu/Zr 基 MAF 被证明用于 ATZ 的电化学传感。超声处理和紫外线/臭氧表面功能化的结合显着增强了二维 MAF 的性能，包括降低电阻、增加比表面积和产生许多活性位点。开发的电化学生物传感器具有高灵敏度 （8.8 μA μM ^-1 cm ^-2 ）、0.236 zM 的低检测限和向 ATZ 的 1 zM 至 1 M 的宽线性范围。此外，在存在多种干扰物的情况下，该器件具有优异的选择性，在环境空气中的保质期长达 60 天。通过检测农业废水和河水中的 ATZ，证明了由表面工程 Cu/Zr-MAF 组成的生物传感器的实际可行性。

 意义和新颖性

MAF 中具有多种价态的 Cu 和 Zr 过渡金属通过配位键促进了 ATZ 的还原，而 2D 结构中增加的氧化活性位点共同加速了电荷转移。结构设计和表面工程之间的这种协同作用最终提高了生物传感器检测 ATZ 的灵敏度和效率。这项工作可以为生物传感器在极低浓度农药电化学检测中的实际应用提供新的视角。