Preparation of hemoglobin imprinted polymers based on graphene and protein removal assisted by electric potential

Hemoglobin (Hb) imprinted polymers based on graphene were prepared on the surface of a Au electrode and protein removal assisted by electric potential was studied in detail. Firstly, the electrode modified with MIP (MIP/AuE) was examined by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Then the electric potential and applying time were carefully investigated. The results of experiments showed that applying an electric potential could improve the efficiency of protein removal and greatly shorten the removal time. Applying +600 mV (vs. SCE) for 60 min was the optimized route for Hb removal in our study. Finally, the MIP/AuE prepared using the optimal conditions was used as a biosensor and successfully applied for the determination of Hb by differential pulse voltammetric (DPV) measurements. The proposed biosensor exhibited a broader linear range and a lower detection limit when it was compared to those Hb sensors based on MIP. The linear range was from 1.0 × 10−8 to 1.0 × 10−2 mg L−1 with a detection limit of 6.7 × 10−9 mg L−1 (S/N = 3). In a word, the work of this paper established a useful way for preparation and template removal based on protein imprinted polymers.