Patent ID: 7908088

Claim:
A method for electronically detecting at least one specific interaction between probe molecules fixed to at least one active zone of a sensor and target biomolecules, wherein said sensor comprises an array of field-effect transistors, each of which has a source region, a drain region, and a gate region which constitutes an active zone on which said specific interaction is to be detected, and wherein said method comprises: a) contacting at least one active zone with a probe molecule of a given type fixed to said active zone, b) contacting at least some of the probe molecules with target biomolecules capable of interacting with said probe molecules in a reaction buffer having a first salt concentration, c) measuring at least one point of a drain current, a source-gate voltage, or a source-drain voltage characteristic of at least one transistor of said array to detect said specific interaction at least for a measurement point obtained in a measuring buffer having a second salt concentration that is lower than the first concentration for probe molecules having been subjected to said specific interaction, said measurement being conducted spatially by means of a difference between said measurement point and a reference point, in said measuring buffer, for two groups of probe molecules fixed to distinct active zones, the measuring point being obtained for probe molecules having been subjected to the interaction of step b) and the reference point being obtained for probe molecules not having been subjected to the interaction of step b).