表面增强拉曼光谱法快速检测水产品中恩诺沙星和环丙沙星残留

SERS Detection of Enrofloxacin and Ciprofloxacin Residues in Seafood

【目的】建立基于表面增强拉曼光谱(surface-enhanced Raman scattering,SERS)检测水产品中恩诺沙星(enrofloxacin,ENR)和环丙沙星(ciprofloxacin,CIP)残留的方法。【方法】以水产品为研究对象,采用粒径(50±5)nm的银纳米溶胶作为SERS增强试剂,200 g·L^(-1)NaCl溶液作为萃取试剂,3 min内判读结果,并建立了峰强度与浓度的线性回归方程,考察线性关系和检出限,对该方法进行评价。【结果】ENR和CIP的拉曼光谱特征峰为532、552、651、737、785 cm^(-1),其中532 cm^(-1)归属于C-N的弯曲振动;552 cm^(-1)归属于C-N面外弯曲振动;651 cm^(-1)归属于C-N、C-C-F面外弯曲振动和C-C=O面内弯曲振动;737 cm^(-1)归属于苯环上C-H的伸缩振动、CC=O的面外弯曲振动、C-C-N弯曲振动;785 cm^(-1)归属于C-H、C-N的面外弯曲振动。通过对ENR和CIP的特征峰(737 cm^(-1))进行定量分析发现拉曼特征峰强度与溶液浓度在10~200 ng·mL^(-1)内有良好的线性关系,R2>0.96,加标回收率为78.4%~106.7%,RSD值为2.1%~6.7%,方法检出限为10μg·kg^(-1)。【结论】该方法准确、快速、稳定,可实现ENR和CIP在水产品中的现场快速筛查检测。

【Objective】A rapid method for detecting residues of enrofloxacin(ENR)and ciprofloxacin(CIP)in seafood by surface-enhanced Raman spectroscopy(SERS)was developed.【Method】On spiked seafood samples,(50±5)nm silver nanoparticles were used as the enhancement reagent and 200 g·L^(-1)NaCl solution as the extraction solution for the SERS assay.Detection results were read within 3 min and mathematical correlation between peak measurement and drug concentration examined.Based on the linearity and limit of detection,optimal assay conditions were determined.【Result】The assay showed several peaks on ENR and CIP standards.The C-N bending vibration caused the peak at 532 cm^(-1),the out-of-plane bending vibration at 552 cm^(-1),the C-N,C-C-F out-of-plane and C-C=O in-plane bending vibrations at 651 cm^(-1),the stretching vibration of C-H on the benzene ring,C-C=O out-of-plane bending vibration,C-C-N bending vibration and C-H,C-N stretching vibration at 737 cm^(-1),and the C-H,C-N out-of-plane bending vibration at 785 cm^(-1).By quantifying the characteristic peak at 737 cm^(-1),a linear relationship with an R2>0.96 was found between the Raman intensity and drug concentration in the range of 10-200 ng·mL^(-1).The assay had a recovery rate of 78.4%~106.7%,RSD of 2.1%~6.7%,and a detection limit of 10μg·kg^(-1).【Conclusion】The newly developed rapid SERS assay for detecting ENR and CIP residues in seafood was deemed accurate,stable,and applicable for field screening and testing.