electrochemical biosensors , methods of making biosensors and methods of detecting a target analyte in a sample to be analyzed are provided . a preferred embodiment device comprises a non - conductive polymer deposited on the electrode to form a matrix material having a plurality of pores ; a capture biomolecule immobilized on the electrode such that the binding of the target analyte to the capture biomolecule effectively blocks a sufficient number of pores in the matrix material to produce a measurable decrease in the rate of a redox reaction occurring at the electrode ; a current source for driving a redox reaction at the electrode ; a redox species in contact with the electrode ; and a detector element operatively connected to the electrode to detect the measureable decrease of a change in the rate of a redox reaction occurring due to the blockage of pores in the matrix material by the target analyte .