Patent ID: 7678256

Claim:
A microfluidic device for assaying at least one analyte specie in a sample comprising a first microchannel intersected by a second microchannel whereby the second microchannel divides the first microchannel into a first part and a second part and the first microchannel divides the second microchannel into a first part and a second part; at least one analyte concentration area in the first part of the first microchannel having insulating structures on or in at least one wall of the first part of the first microchannel which provide a nonuniform electric field in the presence of an electric field provided by off-chip electrodes; a pair of passivated sensing electrodes for impedance detection in a detection area in the first part of the second microchannel; a pair of reference electrodes in a control area in the second part of the second microchannel.