A CMOS Image Sensor for DNA Microarrays

Abstract

An image sensor designed with standard 0.18μm CMOS technology is used to construct a DNA microarray scanner. The detection limit of 4590 fluorophores/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> is compared with 4.49 fluorophores/μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of a commercial photomultiplier-tube-based microarray scanner. The performance gap can be reduced by improving optical coupling, mechanical alignment, laser power supply noise, improved circuit noise and an increase in the conversion gain. The CMOS sensor offers multiple-pixels for reduced scan time and an integrated analog-to-digital converter.