Au@Ag致密单层膜的组装及对农药残留的SERS检测

Assembly of Au@Ag monolayer membrane and SERS detection of pesticide residues

采用聚合物溶液组装法构筑致密Au@Ag核壳单层膜结构,用作SERS基底检测有机磷农药,具有高灵敏性和重现性。Au@Ag核壳纳米立方体首先通过种子生长法合成,然后用功能化的配体聚乙二醇巯基(m PEG-SH)进行修饰获得有序的致密单层膜结构。该结构的形成归因于适量m PEG-SH的加入可以精确调节颗粒间以及颗粒与基底间的相互作用力,使得基底表面的纳米粒子重新排列。这种有序的单层膜结构用作SERS基底具有稳定和高重现的SERS信号,用于检测乙基对氧磷农药残留时检测限低至10^(-8)mol·L^(-1)(2.75μg·m L^(-1))。该聚合物组装方法为构建高灵敏和高重现性的SERS基底提供了一个有效的途径,为SERS技术在农药残留检测领域的推广应用打下了基础。

Au@Ag core-shell monolayer film with dense arrangement was built by a simple polyethylene glycol assembly method, and used as SERS substrate to detect organophosphorus pesticides with highly sensitivity and reproducibility. Au@Ag core-shell nanostructures were synthesized by simple seed growth method firstly, and then modified with methoxypolyethylene glycol mercapto（m PEG-SH） to obtain ordered dense monolayer structure. The formation of this structure attribute to an appropriate amount of m PEG-SH added to precisely regulate the interaction of the particles and between the particles and the substrate. This ordered monolayer nanostructures used as SERS substrates with highly uniform and reproducible SERS signals for the detection of organophosphorus pesticide residues, and the detection limits low to 10-8 mol·L^（-1）（2.75 μg·m L^（-1））. This polymer assembling method provides an effective way to construct a practical SERS substrate with high sensitivity and reproducibility, and gives the basis for the application of pesticide residues detection.