Magnetic Nanowires toward Authentication

Magnetic nanowires (MNWs) have been shown to be promising candidates for nanobarcoding and biolabeling over decades. However, surprisingly, they have never been realized successfully for these applications due to the lack of a reliable encoding strategy that allows reliable decoding of readout signatures. Here, a novel encoding/decoding approach is reported by tailoring the MNWs remanence spectrum that makes decoding the magnetic nanobarcodes feasible even though there is no prior knowledge regarding the readout remanence spectrum. The remanence spectra of several MNWs is tuned by varying their composition, dimensions, and arrangements to generate several distinct nanobarcodes. Furthermore, a simple automated decoding algorithm is illustrated to identify and verify the type and number of MNWs in unknown remanence spectra. The experimental and analytical approaches show that the remanence spectrum is a strong probe for reliable encoding/decoding because it employs three authentication factors that significantly enhance their security performance in nanobarcoding and biolabeling.