Tutorial 2: CMOS Design for DNA Detection Using Ion-Sensitive Field Effect Transistors

In the last decade, we have seen application of CMOS technology in healthcare providing novel solutions for early detection, diagnosis and therapy of disease. Specifically, in the area of DNA sensing and full genome sequencing, whereby the implementation of chemical sensors called Ion-Sensitive Field Effect Transistors (ISFETs) directly in CMOS, has enabled the design of large-scale arrays of millions of sensors which can conduct in-parallel detection of DNA. Furthermore the scaling of CMOS with Moore’s law and the integration capability with microfluidics has enabled commercial efforts to make full genome sequencing affordable by companies such as Ion-Torrent and DNA electronics. In this tutorial, I will first present the fundamentals and physical properties of DNA and how it can be detected using different modalities through the use of CMOS technology. I will then walk the audience through the design of ISFET sensors and instrumentation in CMOS working towards implementing large scale arrays which are currently being used in commercial systems. By the end of the tutorial the audience will have a good understanding of DNA and how it may be sensed in CMOS in addition to the challenges and solutions to be able to design large scale ISFET arrays for DNA detection systems. Tutorial table of contents: • DNA and its physical properties • Applications of detecting DNA • Methods of sensing DNA • Ion-Sensitive Field Effect Transistors (ISFETs) • Principle of operation and non-idealities • Design of ISFETs in CMOS • Design of Instrumentation • State of the art ISFET arrays