Nanocrystalline diamond biosensors
Nanocrystalline diamond is a relatively new material which maintains the outstanding material properties of single crystalline diamond, such as chemical inertness, a large electrochemical potential window, and biocompatibility. Moreover, the smooth nanocrystalline films (roughness rms down to 10 nm) possess interesting mechanical, tribological, and electrical properties owing to the small grain size. This offers a unique opportunity for the integration of biochemical and electronic systems. Nanocrystalline diamond thin films can be deposited on different substrates (silicon, glass, metals, etc) by chemical vapour deposition (CVD). Recently it has been shown that DNA oligonucleotides and enzymes can be immobilized covalently on nanocrystalline diamond surfaces, showing more stability than in the case of DNA immobilized on Si, glassy carbon, or Au.
Our group is currently working on the functionalization of diamond surfaces with biomolecules, as well as on the study of the charge transfer processes between the immobilized biomolecules and the diamond surface. The aim of this work is the development of diamond-based electrochemical biosensors, which offer many advantages compared to other material systems. This work is supported by DFG (SFB 563).
