By applying nonequilibrium Green’s function formalism combined with first-principles density functional theory, we investigate the electronic transport properties of an anthracene-based optical molecular switch. The molecules that comprise the switch can convert between the monomer and dimer forms upon photoexcitation, and two forms can keep stable over a wider temperature range. The transmission spectra of two forms are remarkably distinctive. Theoretical results show that the current through the monomer form is significantly larger than that through the dimer form, which suggests that this system has attractive potential application in future molecular switch technology.

The limited sensitivity of serological tests for mycobacterial antigens has encouraged the development of a nanoparticle probe specific for the extrapulmonary form of Mycobacterium tuberculosis (Mtb). We developed an innovative probe comprised of super-paramagnetic iron oxide (SPIO) nanoparticles conjugated with Mtb surface antibody (MtbsAb-nanoparticles) to provide ultrasensitive imaging of biomarkers involved in extrapulmonary Mtb infection. MtbsAb-nanoparticles were significantly conjugated with Mtb bacilli. The extent of contrast enhancement reduction on magnetic resonance imaging (MRI) for Mtb and human monocytic THP1 cells was proportional to the concentration of MtbsAb-nanoparticles. When MtbsAb-nanoparticles were intravenously injected into mice bearing Mtb granulomas, the granulomatous site showed a 14-fold greater reduction in signal intensity enhancement on T(2) -weighted MR images compared with an opposing site that received PBS injection. Mtb sAb-nanoparticles represent a new non-invasive technology for the diagnosis of extrapulmonary Mtb.