Electronic Detection of DNA Hybridization: Toward CMOS Microarrays

Low-cost mass fabrication methods and label-free capacitive biosensors are needed for many applications. This article presents a electronic microarrays, with single-chip implementations in CMOS technology. Although biochemical operations in CMOS-based arrays are almost the same as in optical devices, the simple readout of integrated CMOS sensors greatly facilitates system integration. These chips can perform a significant amount of sensor data processing and produce digital output signals in standardized form. They can be easily connected to simple, inexpensive, handheld or even wearable readers. However, these devices are in their infancy. Only a small subset of them are at the level of complete single-die integration of sensors, transducers, and data-conditioning circuits. Our purpose in this article is to outline the main technology, design, and implementation challenges involved in developing these highly integrated research prototypes.