i3N|CENIMAT, Departamento de Ciência dos Materiais, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516, Caparica, Portugal.
UCIBIO, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, Campus de Caparica, 2829-516, Caparica, Portugal.
Sci Rep. 2019 Nov 29;9(1):17922. doi: 10.1038/s41598-019-54380-y.
Throughout the last decade, the expansion of food testing has been gradually moving towards ordinary high throughput screening methods performed on-site. The demand for point-of-care testing, able to distinguish molecular signatures with high accuracy, sensitivity and specificity has been significantly increasing. This new requirement relies on the on-site detection and monitorization of molecular signatures suitable for the surveillance of food production and processing. The widespread use of antibiotics has contributed to disease control of livestock but has also created problems for the dairy industry and consumers. Its therapeutic and subtherapeutic use has increased the risk of contamination in milk in enough concentrations to cause economic losses to the dairy industry and have a health impact in highly sensitive individuals. This study focuses on the development of a simple Surface-Enhanced Raman Spectroscopy (SERS) method for fast high throughput screening of tetracycline (TET) in milk. For this, we integrate a paper-based low-cost, fully recyclable and highly stable SERS platform, with a minimal sample preparation protocol. A two-microliter sample of milk solutions spiked with TET (from 0.01 to 1000 ppm) is dried on a silver nanoparticle coated cardboard substrate and measured via a Raman spectrophotometer. The SERS substrate showed to be extremely stable with a shelf life of several months. A global spectrum principal component analysis approach was used to test all the detected vibrational modes and their correlation with TET concentration. Peak intensity ratios (455 cm/1280 cm and 874 cm/1397 cm) were found to be correlated with TET concentrations in milk, achieving a sensitivity as low as 0.1 ppm. Results indicate that this SERS method combined with portable Raman spectrometer is a potential tool that can be used on-site for the monitoring of TET residues and other antibiotics.
在过去的十年中,食品检测的扩展逐渐朝着现场进行普通高通量筛选方法的方向发展。对能够以高精度、灵敏度和特异性区分分子特征的即时检测的需求显著增加。这种新的需求依赖于现场检测和监测适合食品生产和加工监测的分子特征。抗生素的广泛使用有助于控制牲畜疾病,但也给乳制品行业和消费者带来了问题。其治疗和亚治疗用途增加了牛奶中足以造成乳制品行业经济损失并对高度敏感个体产生健康影响的抗生素浓度污染的风险。本研究专注于开发一种简单的表面增强拉曼光谱(SERS)方法,用于快速高通量筛选牛奶中的四环素(TET)。为此,我们整合了一种基于纸张的低成本、完全可回收和高度稳定的 SERS 平台,以及一种最小的样品制备方案。将含有 TET(从 0.01 到 1000 ppm)的牛奶溶液的两微升样品滴在涂有银纳米粒子的纸板基底上,并通过拉曼分光光度计进行测量。SERS 基底具有极好的稳定性,保质期长达数月。使用全局光谱主成分分析方法来测试所有检测到的振动模式及其与 TET 浓度的相关性。发现峰强度比(455 cm/1280 cm 和 874 cm/1397 cm)与牛奶中的 TET 浓度相关,灵敏度低至 0.1 ppm。结果表明,这种与便携式拉曼光谱仪结合的 SERS 方法是一种潜在的工具,可以现场用于监测 TET 残留和其他抗生素。