developed a method for maintaining the target enzyme at the gate sensing using magnetic nanoparticles, where lipase was immobilized onto magnetic nickelferrite nanoparticles, and then the resulting enzyme-modified
nanoparticles could be retained at the gate surface because the magnet continued to run from the
bottom of ISFET gate, as shown in Figure 5. The advantages of the proposed method underlie (1)
improved mass transfer, (2) possibility to be applicable for use in a multiple detection system based on
FET device, and (3) increased amount of bound enzyme on the surface.