超支化卟啉基聚合物荧光探针检测水中汞

Study of a fluorescence probe based on hyperbranched porphyrin-based polymer for the detection of Hg^(2+) in water

制备了一种基于四羧基苯基卟啉(TCPP)的水溶性荧光探针(PEI-TCPP),PEI-TCPP对Hg^(2+)有很好的特异性识别作用,与Hg^(2+)形成的配合物稳定,其结构并不随时间、温度的增大而改变。在pH 5.0~7.5范围内,PEI-TCPP对Hg^(2+)的识别作用最强、结构最稳定;PEI-TCPP对水溶液中Hg^(2+)的检测限为50 nmol/L。根据Benesi-Hildebrand公式和工作曲线,用滴定法考察了PEI-TCPP与Hg^(2+)的作用机理,结果显示其络合比为1:1,络合常数K_a为13.0 L/mmol。

A hyperbranched porphyrin-based polymerfluorescent probe （PEI-TCPP） was prepared to investigate its sensitivity and specificity of trace Hg^2＋ in water. Among various metal ions, PEI-TCPP was found to have a specific recognition to Hg^2＋, and with increasing time and temperature, the complex of PEI-TCPP with Hg^2＋ was stable without structure changing. When pH was 5.0 -7.5, PEI- TCPP had a good recognition to Hg^2＋ , and the complex of PEI-TCPP with Hg^2＋ wasstable. In this experiment, limit of detection of PEI-TCPP to Hg^2＋ was 5.0× 10^-8 mol/L. Stoichiometrie ratio of PEI- TCPP with Hg^2＋, calculated by Benesi-Hildebrand equation and Job ＂s curve through UV absorption titration curve, was 1：1, and binding constant （Ka） was 13.0 L/mmol.