表面活性剂增溶比率荧光Zn2+检测方法研究

合成了一种新的Zn2+荧光检测试剂8-(2-(十八氨基)乙酰氨基)喹啉(AQZ-18)。通过自发荧光的非离子表面活性剂OP-10增溶AQZ-18,获得了一个与Zn2+结合后在320 nm和505 nm分别有两个荧光发射峰的溶液体系。短波长荧光峰来自OP-10,荧光峰强度不随Zn2+浓度变化;长波长荧光峰来自AQZ-18,荧光峰强度随Zn2+浓度增加而增强。利用上述两个荧光峰强度随Zn2+浓度变化时的比值变化建立了一种新的比率荧光Zn2+检测方法。研究表明,Zn2+与AQZ-18形成1∶1型基态配合物,其表观结合常数为1.1×106L/mol。常见金属离子对Zn2+荧光检测无干扰,Zn2+浓度在0～1.1×10-5mol/L范围内与荧光强度变化的比值呈良好的线性关系,相关系数(r2)为0.996 2,检出限为55 nmol/L。该方法可用于水样中Zn2+的检测。

Study on the Ratiometric Fluorescence Detection of Zn2+ Based on Surfactant Solubilization

A novel fluorescent sensor,8-(2-(octadecylamino)acetylamino)quinoline(AQZ-18),was synthesized for sensing Zn2+.Two fluorescence peaks at 320 nm and 505 nm were observed in the solution of AQZ-18,non-ionic surfactant OP-10 and Zn2+.The shorter wavelength peak arised from autofluorescent OP-10 kept almost unchanged,while the longer wavelength peak produced by AQZ-18 increased gradually with increase of Zn2+ concentrations.Base on this,a new ratiometric method was established by measuring the ratio variations of fluorescence intensities in the two regions.The 1 ∶ 1 ground state complex between Zn2+ and AQZ-18 was formed,and the apparent association constant was obtained to be 1.1×106 L/mol.Some common metal ions had no obvious interference for AQZ-18 to detect Zn2+.The ratio of two fluorescence intensities presented a linear relationship with concentration of Zn2+ in the range of 0-1.1×10-5 mol/L(r2=0.996 2),with a detection limit of 55 nmol/L.The method could be used for the determination of Zn2+ in water samples.