The paper presents results of the research aimed at the engineering of nanostructures (NSs). SnO2 nanowires (NWs) were grown via vapor-solid mechanism at a synthesis temperature of 900°С in a modified set-up allowing the NS morphology be encoded in a programmable way along its length. The Ti/Au (20/500 nm) electrical contacts to individual NWs were deposited via consequent PVD vacuum deposition process to obtain gas sensitive chemiresistors. Electrical properties and gas-sensing performance of the obtained monocrystalline NSs with a modified shape were investigated using hydrogen and oxygen gases. It was established that structurally modified NWs, due to the presence of narrow segments, exhibit better gas-sensitive characteristics in comparison with straight NWs. Obtained results are discussed from the positions of single-crystal “neck” formation in NSs and their influence on transport properties of NWs. 1. Introduction