基于SERS技术的果蔬表皮农药残留快速检测方法研究

Study on Rapid Detection of Pesticide Residues on Fruit and Vegetable Surfaces Based on SERS Technology

果蔬表皮农药残留关乎食品安全问题。本文以苹果为研究对象,应用表面增强拉曼光谱(SERS)技术,结合高灵敏度、便携的纳米检测棒,检测果蔬中常用农药倍硫磷和多菌灵,研究农药残留衰减规律,并对比研究不同方法对农药残留的去除效果。研究表明,基于GMA-EDMA多孔材料和金纳米颗粒制备的纳米检测棒,对苹果表皮残留的倍硫磷和多菌灵的最低检测浓度分别达0.10和0.05 mg/L,在低浓度范围内特征峰强度与浓度成良好的线性关系。苹果表皮两种农药残留量随时间成e指数衰减,衰减为e-1的时间常数分别约为1~2 d和4~5 d。不同清洗剂(清水、盐水、小苏打水、果蔬洗涤剂)对农药残留的清洗效果不同,淡盐水可提高农药残留清洗效率,清水清洗需要延长清洗时间才能达到相同效果。研究结果表明,纳米检测棒能有效提高果蔬农药残留的检测灵敏度和检测效率,结合便携式拉曼系统,可实现果蔬农药与淡盐水残留的快速、现场检测。

Pesticide residue on fruit and vegetable surfaces affect to food safety.In this paper,a portable nano detection stick based on the GMA-EDMA porous material and gold nanoparticles was prepared for pesticide detection.Surface enhanced Raman spectroscopy(SERS)technology combined with highly sensitive and portable nano detection stick was used to detect the common pesticides,fenthion and carbendazim,furthermore,study the effect of pesticide residues removal from fruit and vegetable surfaces with different methods.The results showed that the lowest detection concentration of fenthion and carbendazim which detected directly with the nano detection stick,was both 0.05 mg/L,and there was a good linear relationship between peak intensity and concentration in the low concentration range,which could provide a quantitative model for quantitative detection of pesticide residues.The minimum detectable concentrations of residual fenthion and carbendazim at apple peels were 0.10 and 0.05 mg/L,respectively,using the pesticide detection sticks.In the low concentration range the characteristic peak intensity and concentration have a good linear relationship;apple peels pesticide residue was e index decay over time,the time constant is about 1~2 days and 4~5 days;different cleaning agents(water,salt water,baking soda,fruit and vegetable detergents)have different cleaning effects on pesticide residue.Salt water can improve the cleaning efficiency of pesticide residues.Water cleaning needs to extend the cleaning time.The research shows that the detection stick can effectively improve the detection sensitivity and detection efficiency of pesticide residues at apple peels.Combining the portable Raman system,rapid and on-site detection of pesticide residues in apple epidermis can be achieved.