A magnetic molecule detection system - a comparison of different setups by computer simualtion

A new scheme of combined movement by on-chip currents and detection of magnetically labeled biomolecules has been introduced. This was the first step on the way to an on-chip laboratory. A conductor pair has been placed to this end on both sides of the sensor with the possibility of parallel or series connection. This connector setup made it possible to magnetize the beads and move them over the sensor area. This bead motion caused the detection signal. Magnetoresistance curves were measured and micromagnetic calculations have been done for the sensor types: giant magnetoresistance and tunneling magnetoresistance. The results showed an increase in sensitivity and also a corresponding change in the GMR curve. This therefore established an ideal sensor for the bead detection up to large values of bead surface concentration