This disclosure describes, in one aspect, a device for electrochemical quantitation of autoantibodies. Generally, the device includes a housing that defines a plurality of channels and at least two reaction zones. A first reaction zone includes a porous membrane and a first electrode assembly in fluid communication with a first channel. The first reaction zone also includes a first plurality of autoantigens immobilized to the porous membrane. The first electrode assembly is in communication with an amperometric reader. A second reaction zone includes a porous membrane and a second electrode assembly in fluid communication with a second channel. The second reaction zone includes a second plurality of autoantigens immobilized to the porous membrane. The second electrode assembly is in communication with the amperometric reader. Finally, the device includes a source of negative pressure in fluid communication with the first reaction zone and the second reaction zone.