酶联适配体传感器比色检测牛奶中恩诺沙星残留

Colorimetric Detection of Enrofloxacin Residues in Milk Based on Enzyme-linked Aptasensor

通过裁剪分析和共聚焦成像鉴定了适配体的结合域,根据结合域位于3′端茎-环的特点,建立了外切核酸酶Ⅰ依赖的酶联核酸适配体比色分析法检测恩诺沙星残留。波长450 nm吸光度与恩诺沙星浓度呈线性关系,方法的线性范围为36~254μg/L,检测限为15μg/L。实际试样检测显示:15个牛奶样本里有6个检出恩诺沙星残留,残留量在43~152μg/L之间。标准加入回收实验的平均回收率在93.5%~99.6%之间,批内变异系数为6.03%~8.12%,批间变异系数为7.31%~13.42%。该方法操作简便、快速,灵敏度高、特异性强,适合批量样品快速分析和现场快速检测。

The binding domain of aptamer was investigated through croppping analysis and confocal imaging.Based on the characteristic that the binding domain is located at the 3′end of stem-loop,an exonuclease I-dependent enzyme-linked aptasensor has been developed for colorimetric detection of enrofloxacin residue.The absorbance at 450 nm has a linear relationship with the concentration of enrofloxacin.The limit of detection for the method is 15μg/L and the linear range is 36-254μg/L.The test results of real samples showed that 6 of the 15 milk samples were found to contain enrofloxacin residues and the residual amount was between 43-152μg/L.Standard addition recovery experiments showed that the average recoveries was between 93.5%-99.6%,the intra-batch variation coefficient was from 6.03%to 8.12%,and the inter-batch variation coefficient was from 7.31%to 13.42%.This method has high sensitivity,specificity,simple and fast operation,and is suitable for rapid analysis of batch samples and rapid detection in the field.