Proximity effect of magnetic permalloy nanoelements used to induce AMR changes in magnetic biosensor nanowires at specific receptor sites

Abstract

We present simulated, substrate bound, permalloy nanowires with receptor sites for magnetic, aqueously suspended nanoelements that are able to induce an anisotropic magnetoresistive effect in nanowire circuits. The permalloy nanoelements were also simulated to determine the remanent spin configuration and were designed to be bound by antibody mediated interactions with biological ligands at the receptor sites in order to act as a biosensor. All results were simulated using micromagnetic simulations by the Object Oriented Micromagnetic Framework (OOMMF). The simulations revealed that anisotropic magnetoresistive changes were induced at the bridging sections between adjacent nanowires, next to the receptor sites, which connect the two adjacent nanowires. The electrical resistance across the nanowires reduced after the inclusion of the nanoelements at the receptor sites. We therefore conclude that this nanowire configuration is useful for an inexpensive diagnostic biosensor.