文摘
A novel polymer/room-temperature ionic liquid (RTIL) composite material based on chitosan (Chi) and 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIM·BF4) was explored. The composite system can be readily usedas an immobilization matrix to entrap proteins and enzymes. Hemoglobin (Hb) was chosen as a model protein toinvestigate the composite system. A pair of well-defined quasireversible redox peaks of hemoglobin were obtainedat the Chi-BMIM·BF4-Hb composite-film-modified glassy carbon (GC) electrode by direct electron transferbetween the protein and the GC electrode. Dramatically enhanced biocatalytic activity was exemplified at theChi-BMIM·BF4-Hb/GC electrode by the reduction of oxygen and trichloroacetic acid. Thermogravimetric analysis(TGA) suggests that the Chi-BMIM·BF4-Hb composite has higher thermal stability than Chi-Hb itself. TheChi-BMIM·BF4-Hb film was also characterized by UV-visible spectra, indicating excellent stability in solutionand good biocompatibility for protein. The unique composite material based on polymer and ionic liquid can findwide potential applications in direct electrochemistry, biosensors, and biocatalysis.