化学发光生物传感器法测定食品中有机磷与氨基甲酸酯类农药残留

Determination of organophosphorus and carbamates pesticide residues in foods by chemiluminescence biosensor

中文关键词:  有机磷  氨基甲酸酯  乙酰胆碱酯酶  微流控芯片  化学发光  生物传感器

英文关键词:organophosphorus  carbamates  acetylcholinesterase  micro-fluidic chip  chemiluminescene  biosensor

中文摘要:

      目的 构建一种用于检测食品中有机磷与氨基甲酸酯类农药残留的高灵敏度生物传感器, 建立一种用于测定食品中两类农药残留的新方法。方法 以固定化乙酰胆碱酯酶(AChE)为识别元件与底物碘化硫代乙酰胆碱(ATCI)特异性反应, 采用微流控芯片与化学发光仪作为检测元件, 以鲁米诺与铁氰化钾作为化学发光体系, 通过流动注射分析法来检测农药残留。结果 当有机磷类农药辛硫磷、敌敌畏、乐果浓度范围分别在0.1~10、0.08~10、0.8~15 μg/mL时, 相关系数分别为0.9923、0.9903、0.9904, 检出限分别为0.047、0.054、0.388 μg/mL; 当氨基甲酸酯类农药克百威、西维因、灭多威浓度分别在0.08~15、0.1~10、0.1~10 μg/mL时, 相关系数分别为0.9926、0.9972、0.9944, 检出限分别为0.049、0.051、0.080 μg/mL。传感器性能评价实验结果显示, 在最佳条件下对辛硫磷、敌敌畏、乐果、克百威、西维因、灭多威分别测定6次, 结果RSD值均小于7%, 精密度较好; 以碘化硫代乙酰胆碱(ATCI)为底物, 连续通入鲁米诺与铁氰化钾化学发光体系6次, 所得RSD值小于8%, 稳定性较好; 将实验制备的固定化AchE储存于pH值为8.0的磷酸盐缓冲溶液中, 每隔10 d测一次化学发光峰值, 结果显示两个月内相对活力下降为23%, 保存时间较长; 将传感器用于测定包菜、苹果样品中的农残, 添加回收率在90%~99%之间, 显示精密度较好, 可用于测定食品中的农药残留量。结论 此生物传感器性能良好, 适用于测定食品中的有机磷与氨基甲酸酯类农残。

英文摘要:

      Objective To create a high-sensitivity biosensor for detecting organophosphorus and carbamates pesticides in foods and establish a new method to determine these two kinds of pesticides. Methods Immobilized acetylcholinesterase (AchE) was used as recognition element of the sensor, reacting specifically with the substrate of acetylthiocholine iodide(ATCI), the micro-fluidic chip with CL analyzer was used as detecting element, and luminol-potassium ferricyanide system was used in chemiluminescence system. Results When the concentration of proximal, dichlorvos, dimethoate ranging from 0.1~10, 0.08~10, and 0.8~15 μg/mL, respectively, the correlation coefficients were 0.9923, 0.9903, and 0.9904, and the detection limits were 0.047, 0.054, and 0.388 μg/mL, respectively. When the concentrations of carbofuran, carbonyl, and methomyl were ranging from 0.08~15, 0.1~10, and 0.1~10 μg/mL, respectively, the correlation coefficients were 0.9926, 0.9972, and 0.9944, and the detection limits were 0.049, 0.051, and 0.080 μg/mL, respectively. The evaluation of biosensor performance indicates good precision, when determining all 6 kinds of pesticides under optimal conditions, RSD was below 7%; when the substrate of ATCI was injected into chemiluminescence system 6 times discontinuously, RSD was below 8%, which indicated good stability; immobilized AChE was stored in phosphate buffer(pH=8.0), detecting activity every 10 d, lasting for two months, the relative enzymatic activity decreased only 23%, indicating a good storage stability; the biosensor was used to detect samples of cabbage and apple, fortified recoveries were between 90%~99%. Conclusion This biosensor has a good performance, therefore it can be used to determine pesticides in foods.