一种基于共振瑞利散射和荧光增强并对Fe^(3+)和Fe^(2+)具有高识别作用的荧光方法的研究

A Novel Recognition Method for Fe^(3+) and Fe^(2+) Based on the Resonance Rayleigh Scattering and the Fluorescence Enhancement

本文合成了4-甲基哌嗪-1,8-萘酰亚胺修饰的β-环糊精,该化合物对Fe3+和Fe2+展现出良好的选择性识别能力。当适量的氨水加入到该化合物水溶液中后,溶液体系的荧光被完全猝灭。然而,当Fe3+和Fe2+加入到该溶液体系后,520nm处的荧光信号和416nm处的共振瑞利散射峰均逐渐增强。Fe3+和Fe2+引起的荧光强度和共振瑞利散射强度比值的差异可用于鉴别Fe3+和Fe2+,同时,该方法还展现了较高的灵敏度。本文建立的方法对Fe3+检测的线性范围为1.5×10-5~2.2×10-5mol/L,检测限为1.1×10-5mol/L;对Fe2+检测的线性范围为0.5×10-5~4.2×10-5mol/L,检测限为0.6×10-5mol/L。

The fluorescent β-cyclodextrin bearing 4-（methylpiperazinyl） -1,8-naphthalimide （ compound 1） has been synthesized and characterized. The maximum excitation and emission emerged at 411 nm and 520 nm, respectively. After the addition of 8 × 10-4 mol/L ammonia into compound 1 aqueous solution, the fluorescence emission was quenched completely. However, upon adding Fe3＋ and Fe2＋ , the fluorescence signal of compound 1 enhanced gradually. Meanwhile, a resonance Rayleigh scattering peak at 416 nm increased. The difference of the fluorescence enhancement and the resonance Rayleigh scattering signal can distinguish Fes＋ and Fe2＋ with pronounced sensitivity and selectivity. The method exhibited a linear response for Fe3＋ within the concentration range of 1.5 ×10^-5 -2.2 ×10^-5 mol/L, and the limit of detection was 1. 1 × 10^-5 mol/L. For Fe2＋ , the linear range was 0.5× 10^5 -4.2 × 10^-5mol/L, the corresponding limit of detection was 0. 35 × 10^-5 mol/L.