Department of Analytical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran.
J Fluoresc. 2017 May;27(3):921-927. doi: 10.1007/s10895-017-2027-0. Epub 2017 Jan 11.
Here a simple and sensitive fluorescent assay for detecting Cefixime based on inner filter effect (IFE) has been proven, which is conceptually different from the previously reported CEF fluorescent assays. In this sensing platform, fluorescent carbon dots (CDs) were prepared by one-pot synthesis and was directly used as fluorophore in IFE. The method is based on the complexation reaction between cefixime and palladium ion in the presence of acidic buffer solution (pH 4). The Pd(II)-CEFcomplex was capable of functioning as a powerful absorber in IFE to influence the excitation of fluorophore (CDs). Production Pd(II)-CEFcomplex induced the absorption band transition from 310 to 400 nm, which resulted in the complementary overlap with the excitation spectra of CDs. Due to the competitive absorption, the excitation of CDs was significantly weakened, resulting in the quenching of CDs. The present IFE-based sensing strategy showed a good linear relationship from 0.2 × 10 M to 8 × 10 M (R = 0.987) and provided an exciting detection limit of 0.5 × 10 (3δ/slope). The proposed method has been successfully applied for the determination of cefixime in raw milk and human urine samples.
这里证明了一种基于内滤效应（IFE）的简单灵敏的头孢克肟检测荧光分析方法，该方法与先前报道的 CEF 荧光分析方法在概念上有所不同。在这个传感平台中，荧光碳点（CDs）通过一锅合成法制备，并直接用作IFE 中的荧光团。该方法基于酸性缓冲溶液（pH 4）存在下头孢克肟与钯离子之间的络合反应。Pd（II）-CEF 配合物能够作为 IFE 中的强吸收剂，影响荧光团（CDs）的激发。Pd（II）-CEF 配合物的生成诱导吸收带从 310nm 转移到 400nm，这导致与 CDs 的激发光谱发生互补重叠。由于竞争吸收，CDs 的激发显著减弱，导致 CDs 猝灭。基于 IFE 的传感策略显示出从 0.2×10-6M 到 8×10-6M（R=0.987）的良好线性关系，并提供了令人兴奋的检测限为 0.5×10-6（3δ/slope）。该方法已成功应用于生奶和人尿样品中头孢克肟的测定。
