A micro-array bio detection system based on a GMR sensor with 50-ppm sensitivity

摘要: Bio detection is widely utilized in hospitals and laboratories. However, conventional bio methods suffer from long time, complex operation, low sensitivity, these issues prevent their use point of care testing (POCT) applications. Microelectronic are proposed to overcome issues. based on a micro-electronic technique allows easy integration system, leading fast speed simple operation. In this work, fully microelectronic system including sensor design, read-out strategy, data processing GMR biosensor. A chip designed different passivation layer thicknesses tested improve sensitivity. 40 nm thickness realized produce the largest response without oxidization breakdown. order integrate circuit simplify operations, 4-channel biochip fabricated, exhibits super-low output noise corresponding $-116.84$ dBm/Hz at operation frequency. This means that only approximately corresponds signal level five magnetic nanoparticles with diameter 200 nm. reference also cancel unwanted reduce common-mode error Measurements indicate 90% suppression achieved. The measurements reveal sensitivity 50 ppm achieved system.