Molecular recognition-based electronic sensor, which is gateless, depletion mode
field effect transistor consisting of source and drain diffusions, a depletion-mode
implant, and insulating layer chemically modified by immobilized molecular receptors that enables miniaturized
label-free molecular detection amenable to high-density array formats. The
conductivity of the active channel modulates current flow through the active channel when a
voltage is applied between the source and drain diffusions. The
conductivity of the active channel is determined by the potential of the sample solution in which the device is immersed and the device-solution interfacial
capacitance. The
conductivity of the active channel modulates current flow through the active channel when a
voltage is applied between the source and drain diffusions. The interfacial
capacitance is determined by the extent of occupancy of the immobilized
receptor molecules by target molecules. Target molecules can be either charged or uncharged. Change in interfacial
capacitance upon target molecule binding results in modulation of an externally supplied current through the channel.