基于滤纸基底表面增强拉曼光谱法的水中毒死蜱农药的循环快速检测研究

Rapid Circular Detection of Chlorpyrifos in Water by Surface Enhanced Raman Spectroscopy Based on Filter Paper Substrate

该文基于常用滤纸材料,制备了复合银纳米粒子(AgNPs)和ZnO纳米粒子的拉曼检测复合基底材料,建立了复合基底用于毒死蜱农药残留的表面增强拉曼检测方法,并成功实现了对环境水样中毒死蜱的循环稳定检测。所制备的滤纸复合基底材料表面拉曼活性检测位点分布均匀,检测稳定性好,对毒死蜱农药的检出限达48.53μg/L,线性范围50~500μg/L。在紫外光照条件下考察了基底的循环检测稳定性,结果表明,毒死蜱农药在ZnO纳米粒子光催化剂及紫外光照下可实现循环降解,同时检测基底仍能保持高的拉曼检测活性。将该基底材料用于实际地表水中毒死蜱农药的检测,回收率为111%~139%,相对标准偏差不大于12%。所建立的基于复合滤纸表面增强拉曼基底的水中毒死蜱农药残留检测方法,其检出限满足地下水质量标准对农业用水中毒死蜱的限值要求以及食品中农药残留限制标准对水果蔬菜中毒死蜱最大残留限值要求。该方法具有操作简单、耗时短及检测成本低等特点,在农残快速检测方面有巨大的应用潜力。

In this article,a surface enhanced Raman spectroscopy(SERS) based on filter paper substrate was developed for the recyclable detection of chlorpyrifos in water.The substrate was prepared by loading the filter paper with Ag nanoparticles(AgNPs) and ZnO nanoparticles,which has a uniform distribution of hot spot and a good detection stability,and exhibits a high performance in the detection of chlorpyrifos,with a limit of detection(LOD) of 48.53 μg/L and a linear range of 50-500 μg/L.Stability for cycle detection of the substrate was investigated under UV irradiation,and Results showed that chlorpyrifos pesticide could be degraded with ZnO nanoparticles as photocatalyst under the circular irradiation of UV light.Meanwhile,the substrate remained a high Raman activity in each detection.The detection substrate combined with SERS was applied to the detection of chlorpyrifos in real surface water.The spiked recoveries were in the range of 111%-139% with relative standard deviations(RSDs) not more than 12%.The detection limit for chlorpyrifos residues in water based on the fabricated substrate in this paper could meet the limit requirements for groundwater quality standard towards chlorpyrifos in agricultural water and the maximum residue limit value for chlorpyrifos in fruits and vegetables in the pesticide residue limit standard towards food.With the advantages of simple operation,short time-consumption and low cost,this method has a great potential in the rapid detection of pesticide residues.