This talk will be on two topics. The first part is on Cooper pair splitters build on bent segments of carbon nanotubes. Such devices may potentially be used for Cooper pair spin entanglement detection utilizing the intrinsic spin-orbit coupling in the nanotube. Our current experimental effort in this direction and the scheme for entanglement detection will be presented. The second topic is on sub-gap states (Yu-Shiba-Rusinov/Andreev bound states) in InAs nanowire based single and double dots coupled to one superconductor and one normal lead.