**5. Conclusion**

3 Carbon nanowalls and related nanocarbon structures composed of nanographene sheets standing vertically on a substrate have been studied intensively. The mazelike architecture of carbon nanowalls with large-surface-area graphene planes and a high density of graphene edges and domain boundaries could prove useful for a number of different applications. Fabrication techniques of carbon nanowalls and possible applications using carbon nanowalls as nanoplatform in the area of electrochemistry and tissue engineering have been described. A radical injection technique was successfully applied to fabricate straight and large-size monolithic carbon nanosheet. The morphology of carbon nanowalls was controlled by changing the total pressure and input power. In addition, the structure of carbon nanowalls was modified by O2 plasma etching and H2O2 treatment.

Using carbon nanowalls as a platform would be the most promising and important application. Carbon nanowalls were used as electrode to detect several biomolecules. In addition, carbon nanowalls were oxidized by the surface treatment using the atmospheric pressure plasma, and proteins such as bovine serum albumin were immobilized on these surface. Moreover, carbon nanowalls were used as scaffold for cell culturing. The dependence of the cell-culturing rates and morphological changes of HeLa cells on carbon nanowall scaffolds with different densities and wettability were systematically investigated.

Nanoplatform based on vertical nanographene offers great promise for providing a new class of nanostructured electrodes for electrochemical sensing, biosensing, and energy conversion applications.
