A digital CMOS-based 24×16 sensor array platform for fully automatic electrochemical DNA detection.

DNA sensor arrays integrated on CMOS chips allow fully electronic readout of biological information. Compared to state-of-the-art optical methods optical setups are not needed. Key features of fully electronic systems are robust and easy operation. These features enable applications in new fields and markets like diagnosis in doctors' offices, food control, etc. In this article we present a fully integrated system-on-chip design of a digital CMOS DNA-chip, which represents a cost optimized, robust and user friendly solution. Design issues of the chip components are discussed. Measurement results of electrical, electrochemical and DNA tests are presented and demonstrate the functionality. The realized DNA sensor chip is based on chronocoulometric measurement. The scheme of the chip is implemented in a 0.35 μm standard CMOS technology and is extended by an additional backend process dedicated to the gold electrodes. The whole chip with a total of 384 sensor positions captures an area of 15.8 mm(2) and dissipates less than 102 mW. Due to the chip's fully automatic working mode, a complete electrochemical DNA detection can be done in multiple of milliseconds for the whole sensor array. Several electrochemical analysis, such as cyclic voltammetry and chronocoulometric can be done, making the chip multifunctional and flexible but still easy to handle.