Hall Sensor Based System for Detection of Adiponectin Protein

A specific antibody can be bonded to a magnetic bead by the use of an antigen. Because the antibody has this characteristic, we can detect a sample of small amount. After washing the sample, the bonded magnetic bead will be left. Using the hall sensor, we can detect the intensity of magnetic field. Magnetic beads in micrometer size were characterized with regard to the number of beads tested. Magnetic field was detected using the hall sensor. The readout circuit is made of one adder and one subtraction. Because the output of hall sensor is from 0V to 5V, we use PMOS and NMOS input pair amplifier. Compare with traditional Enzyme Linked Immunosorbent Assay (ELISA) colorimetric and NID (Near Infrared), this system is faster than colorimetric, and does not need fluorescence spectroscopy. This system makes use of small sample volume and is low cost.