We have used arrays of individually addressable silicon nanowire
field-effect transistors, which exhibit reproducible highperformance
properties (14, 16), for these experiments. Representative
microscopy images of a silicon nanowire device array
are shown in Fig. 2. The nanowire elements were confined to a
central region that was coupled to a microfluidic channel for
sample delivery; the larger-scale metal electrodes, which are
used for electrical connections to measurement instrumentation,
were passivated with silicon nitride in all areas exposed to
solution. Nanowire elements within the arrays were functionalized
with the same or different virus-specific antibodies as
receptors for selective binding.