基于内滤效应的信号增强型诺氟沙星荧光分析法  

Design of a Sensing System for Turn-on Fluorescence Assay for Norfloxacin Based on Inner-filter Effect

作　　者：耿凤华[1] 王永祥[1] 丁秀云[1] 熊利敏[1] 李国艳[1] 徐茂田[1] 

机构地区：[1]商丘师范学院化学化工学院纳米生物分析河南省高校重点实验室培育基地,河南商丘476000

出　　处：《分析测试学报》2012年第2期195-199,共5页Journal of Instrumental Analysis

基　　金：国家自然科学基金资助项目(21105063;21175091);河南省基础与前沿技术研究计划项目(112300410297);河南省科技攻关计划项目(112102210416;102102210243)

摘　　要：基于茜素红和卟啉之间的荧光内滤效应,成功构建了一种分子识别事件与信号报告空间分离的、高选择性的荧光增强型诺氟沙星分析方法。结果表明,无诺氟沙星时,茜素红在420 nm处有最大吸收,这和卟啉的最大激发波长有较大重叠,茜素红和卟啉之间因发生内滤效应导致卟啉的荧光被有效猝灭;而茜素红与诺氟沙星的配合物在523 nm处有最大吸收,和卟啉的最大激发波长不再重叠,即诺氟沙星与茜素红之间的荷移反应破坏了该内滤效应,导致卟啉荧光恢复,据此,可将茜素红的吸收信号转变为高灵敏的卟啉的荧光信号。在最佳实验条件下,诺氟沙星的质量浓度在10～450 mg.L-1范围内与体系的相对荧光强度(IF/I0F)呈线性关系(r2=0.987 8),检出限(S/N=3)为5 mg.L-1。方法选择性好,常见金属离子和药物辅料不干扰诺氟沙星的测定。该研究利用内滤效应,将灵敏度较低的诺氟沙星紫外可见分析法转换为灵敏度较高的荧光分析法,且无需将分子识别单元和信号转导单元共价连接,无需复杂的荧光探针合成工艺,为设计该类药物的荧光分析法提供了新思路。A highly selective sensing system for turn-on fluorescence assay of norfloxacin（NOR） was proposed based on UV-visible absorption of alizarin red S（ARS） coupled with the use of meso-tetra（N-methyl-4-pyridyl）porphine tetratosylate salt（TMPyP） operative on the fluorescence inner-filter effect（IFE）,in which the combination of two signaling mechanisms allows molecular recoginition event and the signal read-out,independently.The viability of converting the absorption signal of ARS into a fluorescence signal was explored.In the absence of NOR,the absorption spectrum of the ARS has a strong peak at 420 nm,significantly overlapping with the excitation of TMPyP.The formation of NOR-ARS complex shifts the maximum absorbance from 420 nm to 523 nm,which overlap negligibly with the excitation of TMPyP and turn on the proper emission spectrum for TMPyP.Under the optimum conditions,there is a good linear relationship（r2=0.987 8） between relative fluorescence intensity ratio（IF/I0F） of TMPyP and NOR concentration of 10-450 mg·L-1.The limit of detection（S/N=3） was 5 mg·L-1.At the same time,the fluorescence response is highly selective for NOR detection over other metal ions and the common auxiliary materials.The proposed fluorescent NOR assay improved the sensitivity of the UV-Vis method for NOR detection based on the IFE which convert the absorption signal into fluorescent signal.The fluorescent method based on IFE does not require the establishing of any covalent linking between the receptor and the fluorophore.The proposed study offers a novel design to detect drug based on the fluorescence spectroscopy.

关 键 词：内滤效应 诺氟沙星 茜素红 荧光增强法 

分 类 号：O657.3[理学—分析化学] TQ460.72[理学—化学]