Investigation On The Interaction Of Malachite Green Or Rutin With Bovine Serum Albumin In Ionic Liquid-based Aqueous Two-phase System

It is known that volatile organic solvents used to be applied in traditional liquid- liquid extraction. While,the above method must bring pollution our environment. Therefore,it is important to investigate green extraction method which is friendly to our environment. ionic liquid is a kind of green solvent that is investigated these years,moreover,ionic liquid is largely used in the extraction of biomolecular and metal ion and in the synthesis of material. In this dissertation, on the basis of the previous research, the fluorescence spectroscopy combined with UV-visible absorption spectroscopy were used to investigate the interaction of malachite green or rutin with bovine serum albumin in ionic liquid-based aqueous two-phase system.This dissertation consists of four chapters:Chapter 1: The common technologies of extraction and the development of aqueous two-phase system were introduced briefly.Chapter 2: Malachite green (MG)belongs to the triphenylmethane green dye,this new ionic liquid-based aqueous two-phase system(ILATPS),formed by 1-butyl-3-methylimidazolium bromide [Bmim]Br with adding (NH₄)₂SO₄ was successfully applied to simultaneously extract malachite green and BSA under simulated physiologic conditions.The binding constants ,the number of binding sites and the average distance between donor and acceptor were measured at 299 and 309K,which demonstrates that MG can quench the ?uorescence of BSA and the ?uorescence quenching mechanism is probably governed by a static quenching mechanism. The energy transfer from BSA to MG occurs with high probability.The negative enthalpy change (ΔH⁰)and entropy change (ΔS⁰)values of the interaction of MG with BSA in ionic liquid phase demonstrate that the binding of MG with BSA in ionic liquid phase is mainly enthalpy-driven and the entropy is unfavorable for it,van der Waals interactions and hydrogen bonds play important role in the reaction. Conformational changes of BSA in ionic liquid phase investigated by synchronous fluorescence.Chapter 3: this new ionic liquid-based aqueous two-phase system(ILATPS),formed by 1-butyl-3-methylimidazolium bromide [Bmim]Br with adding (NH₄)₂SO₄ was successfully applied to simultaneously extract rutin and BSA under simulated physiologic conditions. the fluorescence spectroscopy combined with UV-visible absorption spectroscopy and electrochemistry method were used to investigate the interaction of rutin with protein and conformational changes of BSA in ionic liquid-based aqueous two-phase system .Chapter 4: Conclusion and outlook.