Characterization of direct immobilized probe DNA on partially functionalized diamond solution-gate field-effect transistors

Amino groups were functionalized directly on the diamond surface after treating 0.5 monolayer of oxidation for detection of DNAs. Also, immobilization of probe DNAs was carried out directly on the partially aminated diamond without linker molecules. Specific hybridization with 21-me.r DNA at a concentration of 10OnM could be clearly detected by two methods, fluorescence microscopy and diamond solution-gate field-effect transistors (SGFETs). DNA hybridization was confirmed using Cy-5-labeled target DNA on a micropatterned diamond surface. The changes in gate potential by the negative charge of immobilized or hybridized DNA were measured on SGFETs and hybridization efficiency on the functionalized diamond surface was estimated as about 40%.