PG-ISFET based DNA-logic for reaction monitoring

A report on the use of programmable gate-ion sensitive field effect transistors (PG-ISFETs) to form DNA-logic gates for reaction monitoring is presented. A PG-ISFET sensor is integrated with standard MOSFETs to form a chemical-inverter that switches when a chemical reaction reaches a certain threshold. By employing feedback to the electrical gate rapid switching is achieved for changes in pH as low as 0.1 units, overcoming limitations of voltage division owing to passivation capacitance of CMOS based ISFETs. Using this, DNA-logic arrays can be synthesised to carry out highly parallel chemical processing functions for applications such as DNA sequencing.