Sensing of molecules by electrochemical detection of nanoparticles

Abstract

The invention relates to a method for sensing target molecules in an analyte solution, a sensor for sensing target molecules in an analyte solution and a measurement system for sensing target molecules in an analyte solution. The method comprises providing a capture surface, wherein a plurality of capture molecules are arranged on the capture surface, each of the capture molecules being configured to bind to at least one of said target molecules. The method further comprises exposing the capture surface to the analyte solution to allow target molecules to bind to the capture molecules arranged on the capture surface. The capture surface is then exposed to a solution containing detection molecules, wherein each of the detection molecules contains an electrochemically active nanoparticle and is configured to bind to one of said target molecules bound to a capture molecule, thereby allowing said electrochemically active nanoparticles to bind to the capture surface through formation of a bond between the respective detection molecule comprising said nanoparticle and one of said target molecules bound to one of said capture molecules arranged on the capture surface. The method further comprises releasing nanoparticles that are bound to the capture surface and, after releasing said nanoparticles from the capture surface, determining an electrical signal at a detection electrode caused by electrochemical reactions of said nanoparticles released from the capture surface.