379Nanowire Field-Effect Transistor Biosensors
A mat sample of In
2
O
3
NWs was grown on a SiO
2
/Si wafer, followed by photolithogra-
phy and metal deposition to pattern an electrode array. The resultant device is shown in
Figure 15.5c. Figure 15.5d and e show typical SEM images of the NW mat sample used in
this study. Multiple nanowires were found bridging the Au electrodes. A SAM of HQ-PA
was created on a freshly cleaned In
2
O
3
NW mat sample. The In
2
O
3
NW device was placed
into the electrochemical cell and completely reduced to HQ-PA. In order to prevent the
thiol terminated DNA from attaching to the gold electrodes, the sample was treated with
dodecane-1-thiol after HQ-PA SAM formation. This resulted in the formation of a SAM of
a C
12
alkyl ch ...