基于氮掺杂石墨烯量子点金属有机框架分子印迹聚合物荧光传感器检测食品中的强力霉素

Determination of doxycycline in foods by molecularly imprinted polymer fluorescence sensor based on nitrogen-doped graphene quantum dots metal-organic framework

目的建立氮掺杂石墨烯量子点金属有机框架分子印迹聚合物荧光传感器检测食品中的强力霉素的分析方法。方法以强力霉素为模板分子,基于氮掺杂石墨烯量子点的光学特性和金属有机框架的高比表面积,结合分子印迹策略,采用“一锅法”制备对强力霉素具有专一性强、灵敏度高的新型分子印迹荧光探针(ZIF-67@N-GQDs@MIP)。结果该探针合成最佳条件为:选用甲醇作为合成溶剂、ZIF-67添加量为20 mg、模板分子:功能单体:交联剂的摩尔比例为1:8:20。在最佳条件下该探针在0.15~5.00 mg/L范围内对强力霉素具有良好的线性关系,检出限低至0.029 mg/L(S/N=3),该方法用于牛奶中强力霉素检测,回收率为90.11%~92.81%。结论该方法构建的分子印迹荧光传感探针具有选择性强、重复性好、灵敏度高、分析时间短、操作简单等优势,适用于复杂样品中痕量强力霉素的快速检测。

Objective To establish a method for the determination of doxycycline in foods by molecularly imprinted polymer fluorescence sensor based on nitrogen-doped graphene quantum dots metal-organic framework.Methods Using doxycycline as a template molecule,based on the optical properties of nitrogen-doped graphene quantum dots and the high specific surface area of metal-organic frameworks,combined with the molecular imprinting strategy,a new molecularly imprinted fluorescent probe(ZIF-67@N-GQDs@MIP)with strong specificity and high sensitivity to doxycycline was prepared by a“one-pot”method.Results The optimal synthesis conditions for ZIF-67@N-GQDs@MIP were as follows:Methanol was determined as the synthesis solvent,the addition amount of ZIF-67 was 20 mg,and the molar ratio of template molecule to functional monomer and crosslinking agent was 1:8:20.Under optimal conditions,the probe has a good linear response to doxycycline in the range of 0.15‒5.00mg/L,and the limit of detection was 0.029 mg/L(S/N=3).The method was applied to the determination of doxycycline in milk,and the recovery was 90.11%‒92.81%.Conclusion The molecularly imprinted fluorescent sensing probe constructed by this method has the advantages of strong selectivity,good reproducibility,high sensitivity,short analysis time and simple operation,and is suitable for the rapid detection of trace doxycycline in complex samples.