Considering that miniaturization is a general trend in biosensor development, the proposed
miniaturized electrode fabricated by MEMS technology is believed to be equal to this tendency. In the
future, the electrode chip may be integrated with an ISFET device, hinting at the potential for it to be
applicable for the development of system-on-chip (SoC) devices. More recently, an attractive approach for exploring conformationally changed protein has been reported by Park et al. [49]. In that study, a new type of ISFET charge sensor was developed for the determination of maltose-induced conformational change in maltose binding protein (MBP). As shown in Figure 4, when treated with maltose on the MBP-modified ISFET surface, the structural transition of MBP took place, leading to a substantial drop in the drain current of the ISFET device. The authors demonstrated
that the ISFET charge sensor can be effectively utilized to evaluate the intramolecular
conformational change in proteins.