The Synthesis And Application Of A UV-Visable Colorimetric Chemosensor For Cu(â…¡) Ion Based On Isonicotic Acid Hydrazide

Copper is one of the vital important elements in nature. It is the important heavy metals and additives for industrial and agricultural processes and important metal nutrients for metabolism of life. Because of various applications, copper can be released into the environment from a variety of sources and pathways and inserted into the human body through the food chain. If the copper ion content in the human body is beyond normal range, the excessive accumulation of Cu2+ in the human body could cause great threat to the urinary system or nervous system. Therefore, establishing an accurate and efficient practical method for detection of copper content in living organisms and the environment is a very meaningful work.Due to the instrument of low price, easy popularization, simple operation and no need of complicated sample preparation process, short analysis time, UV-visible spectrophotometric method is widely used to detect trace metal ions. In this paper, we designed and synthesized a novel copper ion sensor N’-(3,5-di-tert-butyl-2-hydroxy-benzylidene) isonicotinohydrazide(DHIH), and systematically studied its optical properties, recognition performance, sensing mechanism and actual sample detection abilities.In the first chapter, we provided an overview of copper ion including its physiological function and harm, introduced several methods of copper ion detection and research progress in UV colorimetric chemical copper ion sensor.In the second chapter, we introduced the synthesis method of the new copper ion sensor DHIH in detail and carried out its characterization by mass spectrometry, NMR.In the third chapter, we systematically studied the application of chemical sensor DHIH for copper ion detection, including optimized the experimental conditions, discussed the sensing mechanism and actual samples test. At room temperature, addition of Cu2+ to the solution of DHIH in acetonitrile-HEPES buffer solution(7:3, v/v; HEPES 0.1 mol/L; PH=7.0) resulted in a rapid color change from colorless to yellow together with an obvious new absorption band appeared at the range of 400-440 nm. The linear dynamic of Cu2+ ranged from 1.0×10-5 to 1.0×10-4 mol/L and the detection limit was 5.24×10-7 mol/L(3σ). The binding mode between DHIH and Cu(II) was determined according to the Job’s Plot and the proposed sensing mechanism was discussed. The practicability of DHIH as a Cu(II) chemosensor was verified by the experiment of adding standard recovery of real water samples.