Facile Synthesis of Ag Nanoparticles Functionalized Carbon Nanospheres and Application in Direct Electrochemistry of Hemoglobin

摘要

Ag nanoparticles functionalized carbon nanospheres (AgNPs/CNS) were facilely synthesized using in-situ reduction method. The AgNPs/CNS nanocomposites were fully characterized with transmission electron microscope, scanning electron microscope, X-ray diffraction, and energy dispersive spectroscopy. Then, AgNPs/CNS was coated onto glassy carbon electrode surface and used as an electrochemical interface to immobilize hemoglobin to fabricate a novel biosensor. Direct electrochemistry of hemoglobin on the interface based on AgNPs/CNS was investigated by cyclic voltammetry. The experimental results demonstrated that AgNPs/CNS nanocomposites could well maintain the activity of hemoglobin and greatly improve its direct electrochemical behavior. In 0.1 mol L-1 phosphate buffer solution at the pH value of 7.0, hemoglobin, immobilized on the AgNPs/CNS surface, exhibits a pair of nearly reversible redox peaks. The biosensor shows good catalytic property towards the reduction of H2O2. A good linear relationship between the amperometric current response and H2O2 concentration in the range of 2.0 x 10(-6 similar to)1.0 x 10(-3) mol L-1 was obtained with a detection limit of 1.0 x 10(-7) mol L-1 (S/N = 3). The developed AgNPs/CNS interface offers a promising platform for the further study on the biosensor fabrication.