Direct Electrochemistry and Electrocatalysis of Hemoglobin Immobilized in a Polymeric Ionic Liquid Film

A polymer film based on polymeric ionic liquid, which was poly(1-viny1-3-butylimidazolium chloride) (poly(ViBulm(+)Cl(-))for short), was firstly used as matrix to immobilize hemoglobin (Hb). FTIR and UV-vis spectra demonstrated that the native structure of Hb was well preserved after entrapped into the polymer film. The Hb immobilized in the poly(ViBulm(+)Cl(-)) film showed a fast direct electron transfer for the Hb-Fe-III/Fe-II redox couple. Based on the direct electron transfer of the immobilized Hb, polyvinyl alcohol (PVA)/Hb/poly(ViBulm(+)Cl(-))/GC electrode displayed good sensitivity and wide linear range for the detection of H2O2. The linear range of the PVA/Hb/poly(ViBulm(+)Cl(-))/GC electrode to H2O2 is from 3.5 to 224 mu M with a limit of detection of 1.17 mu M. Such an avenue, which integrated polymeric ionic liquid and redox protein via a simple method, may provide a novel and efficient platform for the fabrication of biosensors, biofuel cells and other bioelectrochemical devices.