Single-Molecule Sensing Using Carbon Nanotubes Decorated with Magnetic Clusters

First-principles and nonequilibrium Green's function techniques are used to investigate magnetism and spin-polarized quantum transport in metallic carbon nanotubes (CNT) decorated with transition metal (Ni-13, Pt-13) magnetic nanoclusters (NC). For small cluster sizes, the strong CNT-NC interaction induces spin-polarization in the CNT. The adsorption of a benzene molecule is found to drastically modify the CNT-NC magnetization. Such a magnetization change should be large enough to be detected via magnetic-AFM or SQUID magnetometry, hence suggesting a novel approach for single-molecule gas detection.