A biological sample device for detecting the presence or absence of specific analytes in a sample is provided. A sample, such as a blood or urine sample or a pre-processed tissue sample is collected on a porous pad. A first membrane in liquid communication with the sample pad includes an analyte-specific, electro actively- labeled detection reagent reactive with the an analyte. A second membrane in liquid communication with the first membrane includes a biosensor whose surface has been modified by an analyte-specific capture reagent. The analyte-binding capture reagent immobilizes the analyte electroactive label complex on the surface of the biosensor, whereby direct interaction of the electroactive label with the surface of the biosensor generates an electric signal used by an electronic processing unit to determine whether the analyte is present in the sample.