Patent ID: 8507208

Claim:
A method for detecting a target analyte, the method comprising the steps of: providing a microfluidic device comprising a binding surface in fluid communication with a microfluidic trapping region and at least two electrodes, wherein the microfluidic trapping region comprises a semi-permeable membrane and wherein the binding surface comprises binding molecules capable of selectively binding to the target analyte; providing to the binding surface a first solution comprising the target analyte molecules, wherein at least a number of the target analyte molecules selectively bind to the binding molecules of the binding surface to provide a binding surface having bound target analyte molecules; providing to the binding surface having the bound target analyte molecules a second solution comprising catalyst molecules, wherein at least a number of the catalyst molecules further binds directly or indirectly to the target analyte molecules bound to the binding surface; providing to the binding surface having the bound target analyte molecules and the catalyst molecules a third solution comprising substrate molecules, wherein at least a number of the substrate molecules undergo a catalytic chemical reaction with the catalyst molecules bound directly or indirectly to the target analyte molecules bound to the binding surface, thereby directly or indirectly producing reaction product molecules having an ionic charge different from an ionic charge of the substrate molecules; transporting at least a number of the reaction product molecules into the microfluidic trapping region by applying an electrical potential between the at least two electrodes, wherein at least one electrode is positioned in the microfluidic trapping region and wherein the electrical potential provides a force attracting the reaction product molecules toward the microfluidic trapping region; concentrating the reaction product molecules in the microfluidic trapping region in front of, at a surface of and/or within the semi-permeable membrane; and detecting an amount of the concentrated reaction product molecules in the microfluidic trapping region in front of, at the surface of and/or within the semi-permeable membrane.