一种罗丹明类Hg^(2+)和pH双功能荧光探针及其选择识别性能

Synthesis and Performance of a New Fluorescent Probe Based on Rhodamine for Selective Recognition of Hg^(2+) and pH

以罗丹明B、水合肼和对羟基苯甲醛为原料,合成了一种新型的荧光增强型识别Hg2+和pH双功能荧光探针,即对羟基苯甲醛罗丹明B腙(HRBH)。用FT IR、1 H NMR和13 C NMR对其分子结构进行了表征,并通过荧光光谱对探针的识别性能进行了研究。研究结果表明:当N,N-二甲基甲酰胺(DMF)为溶剂时,探针HRBH对Hg2+具有良好的选择识别性,并且基本不受其他金属离子的影响;通过Job’s曲线可知,探针与Hg2+的配合比为1∶1;Hg2+浓度在3×10-5~7×10-5 mol/L的范围内,探针HRBH的荧光强度与Hg2+浓度呈现出较好的线性关系,线性相关系数为0.9903;探针对pH值的响应区间为3~6,并具有良好的可逆性。

A novel fluorescent probe, p-hydroxybenzaldehyde rhodamine B hydrazone （HRBH）, for detec- ting Hg2＋ and H＋ was synthesized from rhodamine B, hydrazine hydrate and p-hydroxybenzaldehyde. The molecule structure of HRBH was characterized by FT IR, 1H NMR and 13C NMR, and the recognition properties of the probe HRBH were investigated in DMF solution by the fluorescence spectrophotometry. The experimental results show that HRBH exhibits a highly selective recognition for Hg2＋ , and other metal ions do no affct on its recognition for Hg2＋. The complexation ratio of HRBH / Hg2＋ is 1：1 from the method of Job＇s plot by ultraviolet-visble （UV-Vis） absorption spectroscopy. When the concentration of Hg2＋ is in the range of 3×10-5~ 7×10-5mol/L, there is a good linear relationship between the fluo- rescence intensity of the probe HRBH and the concentration of Hg2＋ , and the linear correlation coefficient is 0. 9903. The re probe HRBH can sponse range of the probe HRBH for pH is 3~6, and it has good reversibility. So the be used as a fluorescent sensor for the selective detection of Hg2＋ and pH.