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Electrochemical Biosensor Based on Carbon Ionic Liquid Electrode Modified with Nafion/Hemoglobin/DNA Composite Film
Author(s) -
Sun Wei,
Wang Yan,
Li Xiaoqing,
Wu Jie,
Zhan Tianrong,
Jiao Kui
Publication year - 2009
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200904650
Subject(s) - nafion , ionic liquid , dielectric spectroscopy , charge transfer coefficient , cyclic voltammetry , electrochemistry , electron transfer , biosensor , electrode , chemistry , analytical chemistry (journal) , redox , scanning electron microscope , inorganic chemistry , materials science , nuclear chemistry , organic chemistry , nanotechnology , catalysis , composite material
A new electrochemical biosensor was constructed by immobilization of hemoglobin (Hb) on a DNA modified carbon ionic liquid electrode (CILE), which was prepared by using 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIMBF 4 ) as the modifier. UV‐vis absorption spectroscopic result indicated that Hb remained its native conformation in the composite film. The fabricated Nafion/Hb/DNA/CILE was characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). A pair of well‐defined redox peaks was obtained on the modified electrode, indicated that the Nafion and DNA composite film provided an excellent biocompatible microenvironment for keeping the native structure of Hb and promoting the direct electron transfer rate of Hb with the basal electrode. The electrochemical parameters of Hb in the composite film were further calculated with the results of the charge transfer coefficient (α) and the apparent heterogeneous electron transfer rate constant ( k s ) as 0.41 and 0.31 s −1 . The proposed electrochemical biosensor showed good electrocatalytic response to the reduction of trichloroacetic acid (TCA), H 2 O 2 , NO $\rm{ {_{2}^{-}}}$ and the apparent Michaelis–Menten constant ( K M app ) for the electrocatalytic reaction was calculated, respectively.