基于PS 信号放大策略的SERS 适配体传感器灵敏检测恩诺沙星

利用表面增强拉曼光谱（surface enhanced Raman spectroscopy,SERS）技术检测动物源食品中的抗生素残留操作简便、用时短，但易受基质干扰、灵敏度偏低。该研究利用SERS技术结合磁分离和信号放大策略开发一种高灵敏SERS适配体传感器，用于恩诺沙星的快速检测。首先，利用聚苯乙烯微球（polystyrene microspheres,PS）、4-MBA和互补DNA(complementary DNA,cDNA)构建信号放大型拉曼探针4-MBA@PS@cDNA，利用适配体（aptamer,Apt）和磁珠（magnetic bead,MB）构建捕获探针MB@Apt，并通过碱基互补配对将4-MBA@PS@cDNA和MB@Apt组装成复合探针。结果表明，4-MBA位于1 078 cm-1处的SERS信号强度与恩诺沙星浓度的对数值在1～100 nmol/L具有良好的线性相关关系，决定系数为0.956 6。该方法对恩诺沙星的检出限为0.71 nmol/L，检测牛奶和猪肉中恩诺沙星的回收率为86.67%～128.00%，相对标准偏差为0.4%～1.3%。

A SERS Aptasensor Based on PS-Mediated Signal Amplification Strategy for the Sensitive Detection of Enrofloxacin

It is simple and time-efficient to determine the antibiotic residues in animal-derived food using surface enhanced Raman spectroscopy（SERS），but the technology is susceptible to matrix interference and exhibited low sensitivity.In this paper，a highly-sensitive SERS aptasensor for the rapid detection of enrofloxacin was developed by SERS combined with magnetic separation and signal amplification strategy. First of all，the Raman probe 4-MBA@PS@cDNA with signal amplification function was constructed using polystyrene microspheres（PS），4-MBA and complementary DNA（cDNA）. The capture probe MB@Apt was constructed using aptamer（Apt）and magnetic bead（MB）. The 4-MBA@PS@cDNA and MB@Apt were assembled into a composite probe by base complementary pairing. The results showed that there was a good linear relationship between the SERS signal intensity of 4-MBA at the Raman shift of 1 078 cm-1 and the logarithm value of the enrofloxacin concentration in the range of 1-100 nmol/L，and the coefficient of determination was 0.956 6.The detection limit of enrofloxacin was 0.71 nmol/L，the recovery of enrofloxacin in milk and pork was between 86.67% and 128.00%，and the relative standard deviation varied between 0.4% and 1.3%.