Since the basic concept of using magnetic sensor to detect biomolecules labelled with magnetic particles (MP) was first disclosed by Baselt, significant development has been made on the material and structure of magnetic transducers . The tri-layer spin-valve GMR device can yield 4 times as much signal as the magnetoresistive device mentioned by Baselt . Magnetic tunnel junction (MTJ) device can produce 100 times as much signal as the magnetoresistive devices . In this work, an active biochip consisting of 12 million magnetic-tunnel-junction (MTJ) transducers was developed for high throughput and high sensitivity detection of biomolecules . This chip can detect 12 million different types of molecules simultaneously . 

Magnetics Conference