To get around this, Song et al. [38,39] proposed a diamond solution-gate FETs (SGFETs), in which the surface is not covered by thick insulating layers, and DNA is immobilized directly onto amine-terminated sites, which is a critical factor in terms of sensitivity compared to existing DNA ISFET sensors. The diamond surface channel attached by DNA was exposed directly to the electrolyte lacking gate insulator, thereby leading to a large potential window for diamond up to >3.0 V. The tested device could rapidly detect 3-mer mismatched DNA, and potentially showed the possibility for the monitoring of single-base mismatched DNA, without sacrificing sensitivity.