  We study the emergent proximity effect in mesoscopic circuits that involve a
conventional superconductor and an unconventional pnictide superconductor
separated by a diffusive normal or ferromagnetic wire. The focus is placed on
revealing signatures of the proposed s+- state of pnictides from the
proximity-induced density of states and Josephson current. We find analytically
a universal result for the density of states that exhibits both the Thouless
gap at low energies, and peculiar features near the superconducting gap edges
at higher energies. The latter may be used to discriminate between s+- and s++
symmetry scenarios in scanning tunneling spectroscopy experiments. We also
calculate Josephson current-phase relationships for different junction
configurations, which are found to display robust 0-\pi transitions for a wide
range of parameters.
