Electrochemistry and electrocatalytic of hemoglobin immobilized on FDU-15-Pt mesoporous materials

Abstract In this paper, the composite films of Nafion/Hb/FDU-Pt-15/PDDA were constructed by layer-by-layer assembly technique. The FDU-15-Pt mesoporous materials were synthesized and characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The resulting films were verified by electrochemical impedance spectroscopy (EIS), cyclic voltammetry and UV–vis spectroscopy. The direct electrochemical and electrocatalytic properties of hemoglobin (Hb) in the Nafion/Hb/FDU-15-Pt/PDDA films were also investigated. A pair of stable and well-defined reversible redox peaks was observed and the formal potential of Hb Fe III /Fe II redox couple was found to be − 0.324 V (vs. SCE). Based on a series of optimized conditions, the films modified electrode displayed a good electrocatalytic activity to the reduction of hydrogen peroxide (H 2 O 2 ), which had linear current response from 2.0 × 10 − 6  M to 6.0 × 10 − 2  M with the detection limit of 1.0 × 10 − 6  M ( S / N  = 3). The apparent Michaelis–Menten constant ( K m app ) was determined to be 0.15 mM in the range of lower concentration of H 2 O 2 . The apparent heterogeneous electron transfer rate constant ( k s ) was 1.05 ± 0.03 s − 1 . The good sensitivity, reproducibility, excellent stability and wide linear range make Nafion/Hb/FDU-15-Pt/PDDA a promising application of the preparation of third-generation biosensor.