Hydrogen Peroxide Biosensor Based on Hemoglobin Immobilization on Gold Nanoparticle in FFT Continuous Cyclic Voltammetry Flow Injection System

A novel biosensor was designed for selective determination of hydrogen peroxide in flow injection analysis (FIA) system. The FIA measurement was based on fast Fourier transformation continuous cyclic voltammetry (FFTCCV) detection method in which the charge under the peak current of hydrogen peroxide calculated in a specific potential range. The constructed biosensor is a glassy carbon electrode which is modified by multiwall carbon nanotubes (MWCNTs), gold nanoparticles (AuNPs) and hemoglobin immobilization. The characterization of the modified electrode was studied by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy methods (EIS). The combination of nanoparticles catalyzed electron transfer and amplifying the detection signal. The peak current of hydrogen peroxide on the enzyme activity was proportional to its concentration in the range of 0.1 to 20 mu M, and a detection limit of 20 nM. Experimental parameters affected the sensitivity of the biosensors, including potential scan rate, solution flow rate and buffer pH was studied. The proposed biosensor showed good reproducibility, long-term storage stability and accuracy in analysis.