This paper describes the preparation, characterization, and electrochemical properties of reduced graphene sheet films (rGSFs), investigating especially their electrochemical behavior for several redox systems and electrocatalytic properties towards oxygen and some small molecules. The reduced graphene sheets (rGSs) are produced in high yield by a soft chemistry route involving graphite oxidation, ultrasonic exfoliation, and chemical reduction. Transmission electron microscopy (TEM), X‐ray diffraction (XRD), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS) and Raman spectroscopy clearly demonstrate that graphene was successfully synthesized and modified at the surface of a glassy carbon electrode. Several redox species, such as Ru(NH3)63+/2+, Fe(CN)63−/4−, Fe3+/2+ and dopamine, are used to probe the electrochemical properties of these graphene films by using the cyclic voltammetry method. The rGSFs demonstrate fast electron‐transfer (ET) kinetics and possess excellent electrocatalytic activity toward oxygen reduction and certain biomolecules. In our opinion, this microstructural and electrochemical information can serve as an important benchmark for graphene‐based electrode performances.

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We report on label-free imaging, detection, and mass/size measurement of single viral particles in solution by high-resolution surface plasmon resonance microscopy. Diffraction of propagating plasmon waves along a metal surface by the viral particles creates images of the individual particles, which allow us to detect the binding of the viral particles to surfaces functionalized with and without antibodies. We show that the intensity of the particle image is related to the mass of the particle, from which we determine the mass and mass distribution of influenza viral particles with a mass detection limit of approximately 1 ag (or 0.2 fg∕mm 2 ). This work demonstrates a multiplexed method to measure the masses of individual viral particles and to study the binding activity of the viral particles.influenza virus | human cytomegalovirus | silica nanoparticles | real time detection | solution phase measurement