Microwave-assisted hydrothermal synthesis of Au NPs–Graphene composites for H2O2 detection

Au nanoparticles (NPs) decorated Graphene (Gr) composites were prepared by the reducing agent-free microwave-assisted hydrothermal techniques and employed to immobilize hemoglobin (Hb) to fabricate a novel biosensor. The Au nanoparticles decorated graphene sheets (Au NPs–Gr) composites were characterized by the X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR), Raman spectra and scanning electron microscopy (SEM). Meanwhile, the electrochemical properties were investigated by the cyclic voltammograms (CVs) and amperometric current–time method. The experimental results demonstrated that Au NPs with the diameter of 20 nm were uniformly bestrewed and not aggregated on the surface of the Gr sheets. The resulting biosensor displayed a high sensitivity, good reproducibility, long-time stability, wide linear range from 0.1 to 70 μmol L−1 and low limit of detection with 0.03 μmol L−1 (based on the signal to noise ration = 3) for H2O2 detection.