BIOMEDICAL APPLICATIONS VI: CARBON NANOTUBES AS BIOSENSING AND BIO-INTERFACIAL MATERIALS - Carbon Nanotubes: From Bench Chemistry to Promising Biomedical Applications - page 186

amorphous
SiO 2
vicinal α -SiO 2
lying loop
growing tip
Figure 7.3 CNT falling on the substrate surface with gas low forms a CNT serpentine.
Reproduced from Geblinger et al. 17 with permission.
7.2.2.2 CNT-basedsensors
Possessing novel properties, CNTs have been used as functional materials for
chemical/biological analysis, especially in the area of nano-sensor production.
On the basis of their intrinsic mechanisms, these sensors can be divided into
many subtypes.
7.2.2.2.1 Mass/force sensor
Defect-free CNTs are the materials with the highest strength, low density
and ultra-small cross-sections. Meanwhile, a nanotube can act as a transistor
and thus may be able to sense its own motion. Therefore, CNTs were used to
prepare nano-electromechanical systems proposed to detect mass or force
with ultra-sensitivity. Sazonova et al. 19 reported of suspending CNTs over
a trench (1.2-1.5 μm wide, 500 nm deep) between two metal electrodes
to form a transistor structure. Then a gate voltage was used to induce an
additional charge on the CNTs. The induced opposite charges on the gate