Kang Meiting, Wu Liqing, Zhao Qiang
State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Anal Bioanal Chem. 2025 Aug 13. doi: 10.1007/s00216-025-06052-2.
The overuse of tetracycline antibiotics can lead to its residue in the aquatic ecological environment and subsequently cause risks to human health through the food chain. Therefore, effective determination of oxytetracycline (OTC) residues is urgently needed. In this study, a simple and direct aptamer-based surface plasmon resonance (SPR) sensor has been fabricated and applied for selective and sensitive detection of the antibiotic OTC by using the newly reported short aptamer for OTC. Biotinylated aptamers were immobilized on the surface of a SPR chip functionalized with streptavidin. When OTC bound to its aptamer, the refractive index of the SPR chip changed, and the SPR signal response increased. The SPR chip could be regenerated by simply flowing the running buffer without the need for an additional regeneration solution. We found that a high density of aptamer immobilized on the SPR chip allowed for an enhanced SPR response to OTC. This aptamer SPR sensor had a wide dynamic range of 1.56 nM to 3.2 µM for OTC detection with a detection limit of 3.6 nM. This SPR sensor can be reused and shows high stability. This method demonstrated good specificity towards OTC and enabled us to detect OTC in diluted lake water, showing applicability for OTC detection in practical applications.
四环素类抗生素的过度使用会导致其在水生生态环境中残留，随后通过食物链对人类健康造成风险。因此，迫切需要有效测定土霉素（OTC）残留量。在本研究中，通过使用新报道的针对OTC的短适体，制备了一种基于适体的简单直接表面等离子体共振（SPR）传感器，并将其应用于抗生素OTC的选择性和灵敏检测。生物素化的适体固定在链霉亲和素功能化的SPR芯片表面。当OTC与其适体结合时，SPR芯片的折射率发生变化，SPR信号响应增加。SPR芯片可以通过简单地流动运行缓冲液进行再生，无需额外的再生溶液。我们发现，固定在SPR芯片上的高密度适体能够增强对OTC的SPR响应。这种适体SPR传感器对OTC检测的动态范围很宽，为1.56 nM至3.2 μM，检测限为3.6 nM。这种SPR传感器可以重复使用，并且具有很高的稳定性。该方法对OTC表现出良好的特异性，使我们能够检测稀释湖水中的OTC，显示出在实际应用中检测OTC的适用性。
