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Immobilization and Bioelectrochemistry of Hemoglobin Based on Carrageenan and Room Temperature Ionic Liquid Composite Film
Author(s) -
Sheng Chun,
Zhang Yang,
Wang Lu,
Jia Nengqin
Publication year - 2012
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201200113
Subject(s) - ionic liquid , chemistry , bioelectrochemistry , electrochemistry , hydrogen peroxide , biosensor , electron transfer , composite number , electrode , inorganic chemistry , nuclear chemistry , analytical chemistry (journal) , catalysis , organic chemistry , composite material , materials science , biochemistry
A novel biopolymer/room‐temperature ionic liquid composite film based on carrageenan, room temperature ionic liquid (IL) [1‐butyl‐3‐methylimidazolium tetra?uoroborate ([BMIM]BF 4 )] was explored for immobilization of hemoglobin (Hb) and construction of biosensor. Direct electrochemistry and electrocatalytic behaviors of Hb entrapped in the IL‐carrageenan composite ?lm on the surface of glassy carbon electrode (GCE) were investigated. UV‐vis spectroscopy demonstrated that Hb in the IL‐carrageenan composite ?lm could retain its native secondary structure. A pair of well‐de?ned redox peaks of Hb was obtained at the Hb‐IL‐carrageenan composite ?lm modi?ed electrode through direct electron transfer between the protein and the underlying electrode. The heterogeneous electron transfer rate constant ( k s ) was 2.02 s −1 , indicating great facilitation of the electron transfer between Hb and IL‐carrageenan composite film modi?ed electrode. The modi?ed electrode showed excellent electrocatalytic activity toward reduction of hydrogen peroxide with a linear range of 5.0×10 −6 to 1.5×10 −4 mol/L and the detection limit was 2.12×10 −7 mol/L ( S / N =3). The apparent Michaelis‐Menten constant K M app for hydrogen peroxide was estimated to be 0.02 mmol/L, indicating that the biosensor possessed high af?nity to hydrogen peroxide. In addition, the proposed biosensor showed good reproducibility and stability.