Hydrogen Peroxide Biosensor Based on Polypyrrole-Fullerene-DDAB Nanocomposite Film

A novel polypyrrole-fullerene-didodecyldimethylammonium bromide (PPy-C60-DDAB) was synthesized by an in situ chemical oxidative polymerization method. Scanning electron microscopy (SEM) study showed the morphologies of the nanocomposites. The direct electrochemistry of hemoglobin (Hb) immobilized on the designed PPy-C60-DDAB composite film modified carbon ionic liquid electrode (Nafion/Hb/PPy-C60-DDAB/CILE) and its biosensing for hydrogen peroxide (H2O2) were investigated. The results indicated that direct electron transfer of Hb was realized on the underlying electrode with the usage of the PPy-C60-DDAB nanocomposite film. Moreover, the Nafion/Hb/PPy-C60-DDAB/CILE based sensor showed prominent electrocatalytic activity for the detection of H2O2. The current response was linearly related to the H2O2 concentration in the range from 1 to 114 μM, with a sensitivity of 936 μA mM–1 cm–2 and a second range from 114 to 1479 μM with a sensitivity of 299 μA mM–1 cm–2. The detection limit was 0.3 μM at a signal-to-noise ratio of 3. Thus the PPy-C60-DDAB composite provided by simple synthesis technique will have potential application in studying the electron transfer of enzyme and the design of novel electrochemical biosensors.