Influenza virus solutions containing 108 virus
particles per ml were labeled with DiIC18 (Molecular Probes) in
a manner similar to previous studies (15). Optical data were
acquired by using a Zeiss LSM 510 laser scanning confocal
microscope with PMT detectors and water immersion objective
(60, numerical aperture 1.2). The DiIC18 dye was excited at 532
nm. Bright-field and fluorescence images together with conductance
data were recorded simultaneously. The bright-field data,
which highlight the positions of the nanowire and passivated
metal contact electrodes, and fluorescence data were recorded
simultaneously with two detectors and combined to show the
relative positions of the nanowire and moving virus particles.