UV surface functionalisation of nanocrystalline diamond films for bio-sensing applications
S. Torrengo1,2, A. Miotello1, G. Speranza2 , L. Minati2, M. Ferrari3, A. Chiasera3, M. Dipalo4, E. Kohn4
1 Physics Dep. University of Trento, Povo, 38100 Trento, Italy.
2 FBK-IRST Sommarive str. 18, Povo, 38100 Trento, Italy.
3 CNR-IFN, CSMFO Lab., Via alla Cascata, 56/C, Povo, 38100 Trento, Italy.
4 Institute of Electron Devices & Circuits, Ulm University Ulm, Germany.
The recent advancement in coupling the semiconductor technology with biological molecules has opened new perspectives for the creation of innovative sensors for specific purposes. In this respect, the hydrogenated diamond surface is one of the best platform to develop a biosensor since it possesses rather unique properties. Among the others, diamond has a high chemical inertness and then it is highly biocompatible. Biomolecules grafted on the diamond surface show a higher stability in air and in aqueous environments. Finally the hydrogenated diamond surface is conductive while oxidized diamond is resistive. All these properties are the required ingredients to fabricate a surface gate field effect transistor (SGFET) for an organic label free molecular recognition. To perform the patterned functionalization of the diamond surface needed to realize the SGFET, UV photons are a very convenient tool. In this work we report an XPS and UPS study of a nano-crystalline diamond direct ammination/oxidation using an UV radiation in pure ammonia/oxygen atmosphere.