title: Fluorescence enhancement of imidazolium ionic liquid by its confinement on PVC for in situ selective quantification of hemoglobin.
abstract: A hydrophilic ionic liquid (methylimidazolium chloride, NmimCl)-polyvinyl chloride ionomer (NmimCl-PVC) was prepared by immobilizing and confining N-methylimidazole onto PVC chains. The NmimCl-PVC ionomer exhibits a 4-fold enhancement on the fluorescence intensity with respect to that of NmimCl, attributing to the confinement of ionic liquid by the PVC chain. The fluorescence is excitation-dependent with a maximum at λem 430 nm when excited at 325 nm. In addition, the fluorescence intensity of NmimCl-PVC ionomer increases remarkably with the loading ratio of N-methylimidazole in the range of 4.3-15.1%. The fluorescence quantum yield and lifetime were derived to be 0.112/7.1 ns for the NmimCl-PVC ionomer and 0.063/8.8 ns for NmimCl. Furthermore, hemoglobin is selectively adsorbed by NmimCl-PVC and causes significant fluorescence quenching of the ionomer via dynamic quenching and energy transfer between NmimCl-PVC and hemoglobin. A solid surface fluorimetric procedure was developed for surface adsorption and preconcentration of hemoglobin followed by in situ detection. A linear dynamic range of 0.3-26.2 μg mg(-1) is achieved with a detection limit of 0.1 μg mg(-1). Regarding hemoglobin in aqueous solution, the linear range 5-300 μg mL(-1) is achieved along with a detection limit of 2 μg mL(-1).
authors.affiliation: Institute of Biological Technology, College of Life and Health Sciences, Northeastern University , Shenyang 110189, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Shu
authors.forename: Lu
authors.initials: L
authors.lastname: Han
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wang
authors.forename: Xuwei
authors.initials: X
authors.lastname: Chen
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D002417:Cattle; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007093:Imidazoles / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D006454:Hemoglobins; D007093:Imidazoles; D052578:Ionic Liquids; C029899:imidazole; D011143:Polyvinyl Chloride