Abstract：
Rare earth (RE)-doped CaS phosphors have been widely used as light-emitting components in various fields. Nevertheless, the application of nanosized CaS particles is still significantly limited by their poor water resistance and weak luminescence. Herein, a lattice-matching strategy is developed by growing an inert shell of cubic NaYF4 phase on the CaS luminescent core. Due to their similarity in crystal structure, a uniform core-shell heterostructure (CaS:Ce3+@NaYF4) can be obtained, which effectively protects the CaS:Ce3+ core from degradation in aqueous environment and enhances its luminescence intensity. As a proof of concept, a label-free aptasensor is further constructed by combining core-shell CaS:Ce3+@NaYF4 and Au nanoparticles (AuNPs) for the ultrasensitive detection of kanamycin antibiotics. Based on the efficient FRET process, the detection linear range of kanamycin spans from 100 to 1000 nM with a detection limit of 7.8 nM. Besides, the aptasensor shows excellent selectivity towards kanamycin antibiotics, and has been successfully applied to the detection of kanamycin spiked in tap water and milk samples, demonstrating its high potential for sensing applications.
摘要：
稀土(RE)掺杂的CaS荧光粉作为发光元件在各个领域得到了广泛的应用。然而，纳米CaS颗粒的应用仍然受到其耐水性差和弱发光的限制。在这里，通过在CaS发光核上生长立方NaYF4相的惰性壳来开发晶格匹配策略。由于它们的晶体结构相似，可以获得均匀的核-壳异质结构（CaS：Ce3@NaYF4），有效保护CaS:Ce3+核心在水性环境中的降解,增强其发光强度。作为概念的证明，通过结合核壳CaS：Ce3@NaYF4和Au纳米颗粒（AuNP）进一步构建了无标签的aptasensor，用于卡那霉素抗生素的超灵敏检测。基于高效的FRET过程，卡那霉素的检测线性范围从100到1000nM，检测极限为7.8nM。此外,aptasensor对卡那霉素抗生素表现出优异的选择性，并已成功应用于自来水和牛奶样品中卡那霉素的检测，展示了其在传感应用中的巨大潜力。
