Field-controlled sensor architecture and related methods

Abstract

A nanoelectric field effect sensor uses the field created by the surface charge profile of biomolecular binding to modulate the current flowing between a source and a drain. We have shown that a patterned side or top gate can be used to calibrate the biomolecular field modulation. This approach provides an electrical sensitivity characterization of the sensor before exposing it to sample fluid. Furthermore, a side gate or a top gate voltage with the right sign can be used to control the binding event during functionalization or sensing. For instance, a negative gate voltage can prevent binding of negatively charged proteins on a sensor. This approach of electric-field control of binding can be used in a differential sensor configuration as well. For instance, in a two-sensor single-bridge technique, one of the sensors can be exposed to a local electric field to prevent binding events, which can then be used for background cancellation in a second sensor, not exposed to the electric field. Furthermore, this approach can be used to prepare a sensor chip for multiplexing, where different chip areas can be turned on or off by applying local electric fields.