Laboratorio de Investigación y Desarrollo de Métodos Analíticos (LIDMA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, 47 y 115, 1900 La Plata, Argentina.
Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo Av., Julián Clavería 8, 33006-Oviedo, Spain.
Spectrochim Acta A Mol Biomol Spectrosc. 2023 Jan 5;284:121756. doi: 10.1016/j.saa.2022.121756. Epub 2022 Aug 23.
The growing appearance of antibiotic-resistant strains of microorganisms originated from the widespread use and ubiquitous presence of such drugs is a major concern in the world. The development of methodologies able to detect such substances at low concentration in real water samples is mandatory to overcome this problem. Europium(III) is known to form complexes with tetracycline (TC) with photoluminescent characteristics useful for TC determination. In the present work, we synthesized for the first time carbon nanoparticles (CN) showing delayed photoluminescence using a Europium(III) doping synthesis. The new material (PCNEu) was characterized both morphologically and spectroscopically, showing an analytical photoluminescent signal in presence of TC, arising from the D→F transition of europium, one hundred times higher than that of the europium salt alone in presence of the antibiotic. This enhancement is a consequence of the amplifying effect exerted by nanoparticle structure itself, leading to an efficient synergistic "antenna effect" in the system PCNEu - TC. The analytical signal is affected both by pH and the nature of the buffer used, and it allows the detection of tetracycline in waters with a limit of detection of 2.18 nM and recoveries between 90 and 110%. The analytical performance of the developed methodology enables having lower limits of detection than other luminescent and chemiluminescent reported methodologies.
微生物对抗生素耐药菌株的出现源于此类药物的广泛使用和无处不在，这是全世界关注的主要问题。开发能够在实际水样中低浓度检测此类物质的方法对于克服这一问题是强制性的。已知铕(III)与四环素(TC)形成具有光致发光特性的配合物，可用于 TC 测定。在本工作中，我们首次使用铕(III)掺杂合成法合成了具有延迟光致发光的碳纳米粒子(CN)。新的材料(PCNEu)在形貌和光谱方面都进行了表征，在存在 TC 的情况下表现出分析光致发光信号，该信号源自于铕的 D→F 跃迁，其强度比单独存在抗生素时的铕盐高 100 倍。这种增强是纳米粒子结构本身的放大效应的结果，导致在 PCNEu-TC 体系中产生有效的协同“天线效应”。分析信号受 pH 值和所用缓冲液的性质的影响，并且允许在水中检测四环素，检测限为 2.18 nM，回收率在 90%至 110%之间。所开发方法的分析性能使得检测限低于其他报道的发光和化学发光方法。
