
389Nanowire Field-Effect Transistor Biosensors
was reduced by diluting the serum sample 100 times, which reduced the ionic strength to
1.5 mM. The detection limit of 0.1 U/mL corresponds to a concentration of 10 U/mL in non-
diluted serum, which is much lower than the clinically relevant level for ovarian cancer
diagnosis (100–275 U/mL)
92
and conrmed the feasibility of In
2
O
3
NW sensors for clinical
usage. Figure 15.9e inset shows that the responses (dots) from three independent devices
display consistency. Their linear relationship to biomarker concentration t the Langmuir
isotherm model
61–62
(solid line) and can be used to estimate the CA