Methods and apparatus for measuring analytes using large scale fet arrays

Abstract

Methods and apparatus relating to very large scale FET arrays for analyte measurements. ChemFET (e.g., ISFET) arrays may be fabricated using conventional CMOS processing techniques based on improved FET pixel and array designs that increase measurement sensitivity and accuracy, and at the same time facilitate significantly small pixel sizes and dense arrays. Improved array control techniques provide for rapid data acquisition from large and dense arrays. Such arrays may be employed to detect a presence and/or concentration changes of various analyte types in a wide variety of chemical and/or biological processes. In one example, chemFET arrays facilitate DNA sequencing techniques based on monitoring changes in hydrogen ion concentration (pH), changes in other analyte concentration, and/or binding events associated with chemical processes relating to DNA synthesis.

1 . A method for nucleic acid sequencing, comprising:
 providing an array of chemical sensors, the chemical sensors comprising field-effect transistors having floating gates coupled to sensitive areas arranged along a substantially planar surface;   delivering template nucleic acids proximate to the sensitive areas of the sensors;   introducing a nucleotide to the template nucleic acids; and   detecting output signals from the chemical sensors indicating incorporation of the introduced nucleotide into the template nucleic acids.