诺氟沙星(NOR)和左氧氟沙星(LEV)是临床上最经常使用的两种氟喹诺酮类药物(FQs)。它们的残留严重危害生态系统和人类健康。由于它们在结构和性质上的相似性,迫切需要开发一种高效、灵敏的检测和鉴别策略。在这里,我们首次通过结合N,S共掺杂碳点(CD)和Tb-MOF的前体通过简单的一锅法。CD的引入有效地促进了Tb3+和FQs之间的能量转移,克服了单一Tb-MOFs无法鉴定相似抗生素的局限性。具体来说,NOR的存在通过内部滤波器效应和天线效应导致反向信号响应。这两种机制的协同作用有助于实现伴随着可区分的颜色转变的信号放大。检测限(LOD)为0.036μM。与NOR不同,LEV的加入降低了系统的电子密度,削弱了Tb3+与LEV的协调能力,并以Tb3+荧光强度作为参考信号(LOD=0.383μM)诱导单个信号响应。此外,该方法被证明是快速和直观的,允许直接分析水中的FQs残留物,食物矩阵,和生物样品具有令人满意的精度。通过积分N,具有柔性基板的S-CD@Tb-MOFs,基于纸张的传感器通过读取RGB值促进了FQs的视觉定量测定。所开发的传感器为抗生素的识别和实时监测提供了一种有前途的策略。
Norfloxacin (NOR) and levofloxacin (LEV) are the two most frequently used fluoroquinolones (FQs) in clinic. Their residues seriously endanger the ecosystem and human health. Due to their similarity in structure and properties, it is urgent to develop an efficient and sensitive strategy for detection and differentiation. Herein, we synthesized a novel ratiometric fluorescent sensor for the first time by combining N, S co-doped carbon dots (CDs) and the precursors of Tb-MOFs through a facile one-pot method. The introduction of CDs effectively facilitated the energy transfer between Tb3+ and FQs, overcoming the limitation that single Tb-MOFs could not identify similar antibiotics. Specifically, the presence of NOR resulted in reverse signal response through the inner filter effect and antenna effect. The synergistic effect of these two mechanisms contributed to achieving signal amplification accompanied by a distinguishable color transition. The limit of detection (LOD) was 0.036 μM. Different from NOR, the addition of LEV reduced the electron density of the system, weakened the coordination ability of Tb3+ with LEV, and induced a single signal response with Tb3+ fluorescence intensity as a reference signal (LOD = 0.383 μM). Furthermore, the method proved to be rapid and visual, allowing for the straightforward analysis of FQs residues in water, food matrices, and biological samples with satisfactory precision. By integrating N, S-CDs@Tb-MOFs with flexible substrates, the paper-based sensor facilitated the visual quantitative determination of FQs by reading RGB values. The developed sensor presents a promising strategy for the identification and real-time monitoring of antibiotics.