Magnetic nanowires for quantitative detection of biopolymers

Magnetic nanowires (MNWs) rank among the most promising multifunctional magnetic nanomaterials for nanobarcoding applications, especially biolabeling, owing to their nontoxicity and remote excitation using a single magnetic source. Until recently, the first-order reversal curve (FORC) technique has been broadly used to study the MNWs for biolabeling applications. However, since FORC measurements require many data points, this technique is very slow which makes it inapplicable for clinical use. For this reason, we recently developed a fast new framework, named the projection method, to measure the irreversible switching field (ISF) distributions of MNWs as the magnetic signature for the demultiplexing of magnetic biopolymers. Here, we illustrate the ISF distributions of several MNWs types in terms of their coercivity and interaction fields, which are characterized using both FORC and projection methods. Then, we explain how to tailor the ISF distributions to generate distinct signature to reliably and quantitatively demultiplex the magnetically enriched biopolymers.