Direct electrochemistry and electrocatalysis of hemoglobin immobilized on polyacrylamide-P123 film modified glassy carbon electrode

A novel organic mesoporous material, polyacrylamide-P123 (PAM-P123) composite film, was used to incorporate hemoglobin (Hb) onto the surface of glassy carbon (GC) electrode for studying the direct electron transfer of Hb and fabricating a sensitive biosensor of H2O2. Compared with inorganic mesoporous material, the PAM-P123 composite film has better film-forming property, which is particularly useful for preparing modified electrodes on various substrates for voltammetric measurements. The cyclic voltammetry of Nafion/Hb/PAM-P123/GC modified electrode showed a couple of well-defined and quasi-reversible redox peaks at about 0.317 V (vs. SCE) in pH 7.0 phosphate buffer solution. The Nafion/Hb/PAM-P123/GC modified electrode showed a fast amperometric response and good stability for the detection of hydrogen peroxide. The results indicate that the PAM-P123 film has a promising potential in fabricating third-generation electrochemical biosensors.

► The novel organic mesoporous material PAM-P123 composite film has lamellar structure and biocompatibility.
► The direct electrochemistry of Hb was realized on Nafion/Hb/PAM-P123/GC.
► The electrode reactions showed a surface-controlled process.
► The apparent standard potentials of Nafion/Hb/PAM-P123/GC modified electrode were linearly varied with pH value with the slope of 54 mV/pH.
► The Nafion/Hb/PAM-P123/GC modified electrode showed a fast amperometric response and good stability for the detection of H2O2.