A real-time quantitative biosensing system that anyone can use anywhere is a key technology for the development of a point-of-care testing (POCT) system for health-care and biochemical research applications. There are two methods for emerging real-time quantitative biosensing: optical and electrical methods. Electrical methods do not require fluorescent labeling, and thus, it is cheaper, faster, smaller, and more accurate than optical methods. In particular, on-chip measurement using a large-scale biosensor array exploits the advantages of highly-integrated CMOS circuits, realizes multi-biomolecular detection and improves the accuracy statistically.