Figure 4: (a) The optical images of a patterned GMR bioarray; (b) MR transfer loop of a GMR bioarray before and after MNPs spiked along with sensors with BSAblocking under a magnetic field along the hard-axis bias (transverse); (c) MR transfer loop of a GMR bioarray before and after MNPs spiked along with sensors withBSA blocking under a magnetic field along the easy-axis bias (Longitude). (d) TEM images of the MNP spiked on the sensor surface.