Environmental Microbial and Food Safety Laboratory, Agricultural Research Service, United States Department of Agriculture, 10300 Baltimore Avenue, Bldg. 303 BARC-East, Beltsville, MD 20705, USA.
Hefei Institute of Physical Science, CAS 350 Shushanhu Road, Hefei 230031, China.
Sensors (Basel). 2018 Feb 1;18(2):424. doi: 10.3390/s18020424.
Therapeutic and subtherapeutic use of veterinary drugs has increased the risk of residue contamination in animal food products. Antibiotics such as tetracycline are used for mastitis treatment of lactating cows. Milk expressed from treated cows before the withdrawal period has elapsed may contain tetracycline residue. This study developed a simple surface-enhanced Raman spectroscopic (SERS) method for on-site screening of tetracycline residue in milk and water. Six batches of silver colloid nanoparticles were prepared for surface enhancement measurement. Milk-tetracycline and water-tetracycline solutions were prepared at seven concentration levels (1000, 500, 100, 10, 1, 0.1, and 0.01 ppm) and spiked with silver colloid nanoparticles. A 785 nm Raman spectroscopic system was used for spectral measurement. Tetracycline vibrational modes were observed at 1285, 1317 and 1632 cm in water-tetracycline solutions and 1322 and 1621 cm (shifted from 1317 and 1632 cm, respectively) in milk-tetracycline solutions. Tetracycline residue concentration as low as 0.01 ppm was detected in both the solutions. The peak intensities at 1285 and 1322 cm were used to estimate the tetracycline concentrations in water and milk with correlation coefficients of 0.92 for water and 0.88 for milk. Results indicate that this SERS method is a potential tool that can be used on-site at field production for qualitative and quantitative detection of tetracycline residues.
兽用药物的治疗和亚治疗用途增加了动物食品中残留污染的风险。四环素等抗生素被用于治疗哺乳期奶牛的乳腺炎。在停药期结束前从接受治疗的奶牛中挤出的牛奶可能含有四环素残留。本研究开发了一种简单的表面增强拉曼光谱（SERS）方法，用于现场筛选牛奶和水中的四环素残留。为表面增强测量制备了六批银胶体纳米粒子。制备了七个浓度水平（1000、500、100、10、1、0.1 和 0.01ppm）的牛奶-四环素和水-四环素溶液，并加入银胶体纳米粒子进行掺杂。使用 785nm 拉曼光谱系统进行光谱测量。在水-四环素溶液中观察到四环素振动模式在 1285、1317 和 1632cm 处，而在牛奶-四环素溶液中在 1322 和 1621cm 处（分别从 1317 和 1632cm 处偏移）。在两种溶液中均检测到低至 0.01ppm 的四环素残留。在水中和牛奶中，分别使用 1285cm 和 1322cm 处的峰强度来估计四环素浓度，水的相关系数为 0.92，牛奶的相关系数为 0.88。结果表明，该 SERS 方法是一种潜在的工具，可以在现场生产中用于定性和定量检测四环素残留。
