The present invention relates to a process to carry out two or more enzymatic reactions in a reaction medium, wherein the process comprises providing a system comprising at least two substantially homogeneous and colloidal populations of magnetic nanoparticles (MNPs) and applying one or more external alternating magnetic field to produce the simultaneous or sequential activation of the enzymes functionalized on the surface of each population of MNPs so that the enzymatic reactions can be thermally activated.