Electrochemical biosensors, applications and methods of making biosensors

A biosensor comprising:

• a) an electrode;
• b) a matrix material deposited on the electrode, wherein the matrix material comprises a plurality of pores therethrough;
• c) a capture biomolecule immobilized on the electrode capable of binding a target analyte in a sample to be analyzed, wherein 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;
• and
• d) a detector element coupled to the electrode to detect the measureable decrease in the rate of a redox reaction occurring at the electrode in order to detect the presence of the target analyte due to the number of pores in the matrix material blocked by the target analyte.

A method of making a biosensor comprising:

• a) providing an electrode;
• b) immersing the electrode in a solution of a non-conductive polymer material;
• c) running a current to the electrode sufficient to cause the non-conductive polymer material to deposit on the surface of the electrode, thereby forming a matrix material having a plurality of pores therethrough;
• d) immobilizing an unlabelled capture biomolecule capable of binding a target analyte onto the matrix material, wherein the binding of the target analyte by 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;
• and
• e) coupling the electrode to a signal element to detect and report a change in the rate of a redox reaction occurring at the electrode.

A method of detecting a target analyte in a sample to be analyzed comprising:

• a) immersing an electrode in the sample to be analyzed, wherein the electrode comprises:
• i) a non-conductive polymer deposited on the electrode to form a matrix material having a plurality of pores therethrough, and wherein the matrix material is of sufficient thickness to produce a detectable change in the rate of a redox reaction occurring at the electrode;
• and
• ii) an unlabelled capture biomolecule immobilized on the electrode capable of binding the target analyte contained in the sample to be analyzed, wherein 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,
• b) providing a flow of electrons to drive a redox reaction at the electrode between the electrode and a redox species in contact with the electrode;
• and
• c) detecting and reporting a change in the rate of a redox reaction occurring at the electrode that signals the binding of the target analyte to the capture biomolecule.