以前设计合成的基于香豆素氨基硫脲衍生物的传感器分子L能在含水介质中单一选择性比色识别铜离子.鉴于铜离子能与氰根离子(CN-)结合形成稳定的配合物,在以前工作基础上,研究了L与铜离子形成的配合物对CN-的连续识别性能.结果表明,L与Cu2+能形成稳定的绿色配合物CuL2,该配合物能专一选择性高灵敏度比色识别水中的CN-.在CuL2的DMSO/H2O(V∶V=3∶1)HEPES(N-2-羟乙基哌嗪-N'-2-乙磺酸)的缓冲体系(pH=7.0)中分别加入F-,Cl-,Br-,I-,AcO-,HSO4-,ClO4-,N3-,SO42-,NO3-,SCN-和CN-等阴离子的水溶液后,只有CN-的加入使得溶液颜色由绿色变为无色,同时在紫外光谱中,CuL2在446 nm处的最大吸收峰消失,这一识别过程不受其它阴离子的干扰.CuL2对CN-的裸眼最低检测限为8.0×10-6mol/L,紫外光谱检测限为4.0×10-7mol/L(0.4μmol·L-1),低于世界卫生组织规定的正常饮用水中CN-的含量标准(〈1.9μmol·L-1).结果表明CuL2是一种良好的CN-比色识别受体,在含水介质中对CN-具有选择性好、灵敏度高以及抗干扰强的性能.制备了基于CuL2的CN-检测试纸,该试纸可以方便快捷的检测水中的CN-.
Owing to CN could firmly bind copper(ll) via coordinate bonds, a competitive coordination mechanism based colorimetric chemosensor CuLe was designed and synthesized. We carried out a series of CN recognition research based on this work. As a result, chemosensor CuL2 could colorimetrically detect CN in water solution with specific selectivity and high sensitivity. CuL~ can be utilized as a new colorimetric chemoscnsor fbr detection of cyanide at neutral pH in aqueous condition. U~on the addition of cyanide water solution to the DMSO/H~O (V: V--3 : 1) HEPES buffered solution (pH-- 7.0) of chemosensor CuL2, the green color of chemosensor CuL2 laded to colorless inmlcdiately, in the corresponding UV-vis spectra, the absorption at 446 nm disappeared. The detection limits were 8.0X 10 ~' and 4.0~ 10 7 mol/L of CN using the visual color changes and UV-vis changes respectively, which is lower than the WHO guideline of 1.9 ~,lmoI.L t. Other anions such as F , CI , Br , l , AcO , HSO4, C1O4 , N3 , SO~ , NO3 and SCN had no influence on the probing behavior of CuL, toward cyanide. The CuL2 complex showed a highly selective and sensitive response toward cya- nide by the complexation between the Cu2 and CN . The process can be monitored by UV-vis spectral changes as well as a visual color change. The good selectivity and high sensitivity of the complex CuL2 toward cyanide make CuL2 a promising candidate in practical applications as a good cyanide probe. Considering the simplicity of the analysis and low cost of the starting materials in the present system, this new method may be provided an useful potential candidate of colorimetric chemosensor for determination of cyanide in a variety of biological and environmental systems. Test strips based on CuLe were fabricated, when diffierent anion solutions were added to the test strips respectively, only the addition of CN could induced an obviously color changes, the detection limits of the test strips for CN is 8.0X 10 s mol/L. This test strips could act as a conv