朱松明, 周晨楠, 和劲松, 张雪吟, 郭希山. 基于酶抑制法的农药残留快速比色检测[J]. 农业工程学报, 2014, 30(6): 242-248. DOI: 10.3969/j.issn.1002-6819.2014.06.029
    引用本文: 朱松明, 周晨楠, 和劲松, 张雪吟, 郭希山. 基于酶抑制法的农药残留快速比色检测[J]. 农业工程学报, 2014, 30(6): 242-248. DOI: 10.3969/j.issn.1002-6819.2014.06.029
    Zhu Songming, Zhou Chennan, He Jingsong, Zhang Xueyin, Guo Xishan. Rapid colormetric detection of pesticide residues based on enzyme inhibition method[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2014, 30(6): 242-248. DOI: 10.3969/j.issn.1002-6819.2014.06.029
    Citation: Zhu Songming, Zhou Chennan, He Jingsong, Zhang Xueyin, Guo Xishan. Rapid colormetric detection of pesticide residues based on enzyme inhibition method[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2014, 30(6): 242-248. DOI: 10.3969/j.issn.1002-6819.2014.06.029

    基于酶抑制法的农药残留快速比色检测

    Rapid colormetric detection of pesticide residues based on enzyme inhibition method

    • 摘要: 基于有机磷与氨基甲酸酯类农药对乙酰胆碱酯酶(acetylcholinesterase,AChE)的抑制作用,以吲哚酚乙酸酯为酶促水解反应的显色底物,制备了一种抛弃型农药残留快速检测酶片;通过优化试验,用物理吸附法将AChE固定到尼龙膜Hybond N+膜上,经真空冷冻干燥后,酶活回收率可达27.3%;该酶片显色结果为蓝绿色,通过比较显色强度的变化,酶片对农药标样氧乐果、毒死蜱、甲萘威与抗蚜威的检出限分别为1、0.05、1.5与 0.8 μg/mL,均达到食品中的最大残留限量标准;将研制的酶片用于葡萄汁与小白菜样品的检测结果证实,该酶片具有灵敏度高、准确度高、重现性好等优点,可用于农产品中有机磷与氨基甲酸酯类农药残留的快速定性筛检。

       

      Abstract: Abstract: In recent years, due to the frequently reported food safety events, people generally care about the food safety. According to former research, the application amount of organophosphorus pesticides and carbamate pesticides possesses about 70% of the total application amount of pesticides. So, it is necessary to develop fast, sensitive and accurate analysis of pesticide residues to assure the quality of agricultural products. However, the existing food quality supervision system is generally based on the instrument analysis technology, which is time-consuming and high-costing, and will delay the actual release of information for the food safety determination. So it cannot provide the rapid response to the consumer queries. Therefore, there is an urgent need to develop the rapid detection techniques for food safety.A novel disposable enzyme tablet was developed for rapid colorimetric detection of pesticide residues in agricultural products, which based on the inhibition of acetylcholinesterase (AChE) activity by pesticides and the AChE-catalyzed hydrolysis of chromogenic substrate, indoxyl acetate. As known, indoxyl acetate can be catalyzed to indole with the existence of AChE. Indole was oxidized in air quickly, turning to be blue-green, which could be easily distinguished by the naked eye.Firstly, the AChE was immobilized onto the Hybond N+ nylon membrane. It was a crucial work to choose a suitable immobilization method. In our study, the physical absorption method seemed more easy-operative and suitable than the cross-linking since it rarely has no inference on the results. Besides, immobilization temperature, time and methods of drying were optimized in the immobilization process. The enzymatic tablets were immobilized under 4℃ for 30 min, then freeze-dried in a vacuum chamber, the recovery rate of enzyme activity was as high as 27.3%, which considered to be optimal. The other parameters such as substrate concentration, inhibition time and coloring time were optimized. The results were as follows: the best amount of acetate solution was 10 mmol/L, and the inhibition time and the color develop time were 15 and 10 min, respectively.In the measurement process, the color of the enzyme tablet was blue-green. Through analyzing the changes of color intensity, the limit of detection (LOD) of this assay system were 1 μg/mL for omethoate, 0.05 μg/mL for chlorpyrifos, 1.5 μg/mL for carbaryl, and 0.8 μg/mL for pirimicarb, all of them have attained the requirements of the maximum residue limits in food. Detection results of pesticide residues in real samples of grape and cabbage showed that the enzyme tablet had high sensitivity, high degree of accuracy, and good reproducibility, suggesting its great potential for practical application in rapid qualitative determination of organophosphorus (OP) and carbamate (CM) pesticide residues in agricultural products. Furthermore, this assay has long storage time at 60 days. In sum, this work provides a feasible way to develop fast, sensitive detection for pesticide residue.

       

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