Effects of protein inter-layers on cell-diamond FET characteristics.
Diamond is recognized as an attractive material for merging solid-state and biological systems. The advantage of diamond field-effect transistors (FET) is that they are chemically resistant, bio-compatible, and can operate without gate oxides. Solution-gated FETs based on H-terminated nanocrystalline diamond films exhibiting surface conductivity are employed here for studying effects of fetal bovine serum (FBS) proteins and osteoblastic SAOS-2 cells on diamond electronic properties. FBS proteins adsorbed on the diamond FETs permanently decrease diamond conductivity as reflected by the -45 mV shift of the FET transfer characteristics. Cell cultivation for 2 days results in a further shift by another -78 mV. We attribute it to a change of diamond material properties rather than purely to the field-effect. Increase in gate leakage currents (by a factor of 4) indicates that the FBS proteins also decrease the diamond-electrolyte electronic barrier induced by C-H surface dipoles. We propose a model where the proteins replace ions in the very vicinity of the H-terminated diamond surface.
Rezek
Bohuslav
B
Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnická 10, 16200 Prague 6, Czech Republic. rezek@fzu.cz
Krátká
Marie
M
Kromka
Alexander
A
Kalbacova
Marie
M
D000327:Adsorption; D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D001798:Blood Proteins / Q000737:chemistry*; D002417:Cattle; D002460:Cell Line; D018130:Diamond / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods; D006801:Humans; D007477:Ions; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D012996:Solutions; D013499:Surface Properties; D014173:Transistors, Electronic
D001798:Blood Proteins; D007477:Ions; D012996:Solutions; D018130:Diamond