基于磁性金属有机框架分离的纳米金比色法检测单核细胞增生李斯特菌

Highly Sensitive Colorimetric Detection of Listeria monocytogenes by Using Gold Nanoparticles Based on Magnetic Metal-Organic Framework Separation

以磁性金属有机框架复合材料作为捕获探针,免疫功能化纳米金作为信号探针,建立一种纳米金比色法快速检测单核细胞增生李斯特菌的方法。结果表明:在最适条件下,单核细胞增生李斯特菌的可视化检出限为1.2×10^(3) CFU/mL,紫外光谱检测结果在1.2×10^(1)~1.2×10^(8) CFU/mL范围内有良好的线性关系(Y=0.519-0.043X,R2=0.978),检出限低至0.45 CFU/mL,各浓度梯度的批内变异系数在0.31%~1.30%之间。将单核细胞增生李斯特菌接种到鸡胸肉上进行检测,其加标回收率在91.1%~108.7%之间,变异系数不高于7.4%,且结果与平板计数法一致。本方法具有准确、灵敏、快速等特点,在食源性致病菌检测方面具有较好的应用前景。

In this study,magnetic metal organic framework composites as capture probe and immunofunctionalized gold nanoparticles as signal probe were used to develop a rapid colorimetric method for the detection of Listeria monocytogenes.Under optimal conditions,the visual detection limit for L.monocytogenes was 1.2×10^(3) CFU/mL.The results of ultraviolet spectroscopy showed a good linear relationship in the range of 1.2×10^(1)‒1.2×10^(8) CFU/mL(Y=0.519‒0.043X,R^(2)=0.978),the detection limit was as low as 0.45 CFU/mL,and the intra-batch coefficient of variation of all concentration gradients was between 0.31%and 1.30%.The recoveries for spiked chicken breast were 91.1%‒108.7%with coefficient of variation less than 7.4%,and the result was consistent with that of the plate counting method.In conclusion,the proposed assay is rapid,accurate sensitive,and highly applicable to the detection of foodborne pathogens.