Non-Enzymatic Hydrogen Peroxide Sensor Based on Fe3O4@Polydopamine-Ag Nanocomposite Modified Magnetic Glassy Carbon Electrode

Abstract

A novel electrocatalyst, Fe3O4@Polydopamine-Ag nanocomposite, was successfully synthesized by a facile and environmentally friendly method. Fe3O4 nanoparticles were initially coated with polydopamine (PDA) via self-polymerization. Then, Ag nanoparticles were in situ deposited onto the surface of PDA functionalized Fe3O4 nanoparticles due to the reductive feature of PDA. The as-prepared Fe3O4@PDA-Ag nanocomposite was characterized by TEM, XRD, XPS and VSM. Moreover, antibacterial tests indicated that the Fe3O4@PDA-Ag nanocomposite exhibited excellent antibacterial activity against Escherichia coli. For the fabrication of sensor, Fe3O4@PDA-Ag nanocomposite was firmly immobilized onto the magnetic glassy carbon electrode as a result of the powerful magnetism interaction. The electrochemical behaviors of the sensor were interrogated by cyclic voltammetry and differential pulse voltammetry. The sensor exhibited excellent electrocatalytic activity toward the reduction of H2O2. In the optimum conditions, the linear response range of the constructed H2O2 sensor was from 0.1 to 17.0 mM with a detection limit of 1.6 μM (S/N = 3). In addition, the sensor exhibited long-term stability and good reproducibility, which is a promising analytical tool for the detection of real samples.