Influence of Buffers and Culture Media on Diamond Solution-Gated Field Effect Transistors Regarding Stability and Memory Effect

The transfer characteristics of a nanocrystalline diamond (NCD)-based solution-gated field effect transistor (SGFET) under the influence of inorganic and organic compounds were studied. Studied compounds included three different buffer solutions (Phosphate, HEPES, McIlvaine buffer) and commonly used culture media (fibronectin, albumin and fetal bovine serum). It was found that buffers with the same pH of 7.4 caused different voltage shifts in transfer characteristics. This effect was reversible which indicates the surface stability of the hydrogen-terminated diamond during repeated measurements. In contrast to this observation, the SGFET sensitivity decreased after applying the culture solutions which we attribute to the permanently adsorbed bio-layer formed on the SGFET channel sensing area