Magnetic glass carbon electrode, modified with magnetic ferriferrous oxide nanoparticles coated with molecularly imprinted polymer films for electrochemical determination of bovine hemoglobin

The modified electrode based on magnetic ferriferrous oxide (Fe3O4) nanoparticles covered with molecularly imprinted polymer was fabricated and used for electrochemical recognition of bovine hemoglobin (BHb). First, the magnetic Fe3O4 nanoparticles were covered with silicon dioxide. Then dopamine (DA) was self-polymerized on the surface of magnetic nanoparticles in the presence of bovine hemoglobin as the template molecular. The molecularly imprinted polymers were characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR) and electrochemical impedance spectroscopy (EIS). Potassium hexacyanoferrate (K3[Fe(CN)6]) was used as an electroactive probe for measurement signal. Under optimized conditions (70 min for adsorption, pH = 6.0), the DPV peak current regressed linearly with the BHb concentration increase in the range of 5.0 × 10−7 to 1.0 × 10−5 g mL−1 (r = 0.9939) with a detection limit of 1.184 × 10−8 g mL−1 (S/N = 3). Several proteins were tested to confirm the imprinting effect of the modified electrode. The results showed the good selectivity of the resulting biosensors. The applicability of the method for complex matrix analysis was also evaluated and the modified electrode showed good stability and reproducibility.