Abstract: A device for detecting and quantifying an analyte in a sample and a method of using the device includes a disposable cartridge having a microfluidic inlet for loading the sample having reporter probe-analyte-capture probe-magnetic bead complexes. A purifying chamber for purifying the magnetic bead complexes is also includes, as well as a measure chamber with a chip having electrodes. External electromagnets are situated each on opposite sides of the purifying chamber for retaining, or releasing or shaking magnetic bead complexes present in the purifying chamber. A permanent magnet is located under the working electrode of the measurement chamber to attract and retain the magnetic bead complexes on the surface of the working electrode of the chip. The device further includes a potentiostat for carrying out the electrochemical detection and quantification of the analyte.